The World Design of Hollow Knight: Silksong

Welcome back to Boss Keys. This is my series about the design of games with sprawling, interconnected, maze-like worlds. Including dungeons, alien planets, fantasy kingdoms, and gothic castles. Now the most viewed episode in this series - by far - was on the game Hollow Knight - a modern day masterpiece, and perhaps the finest example of the Metroidvania genre. That's a genre, if you still don't know, that describes games that take place in a single, contiguous world map. Where progress is made through careful exploration, by making connections between abilities... and obstacles, and by slowly untangling the knot at the centre of the world. Now Hollow Knight did this with aplomb. And then combined it with beautiful graphics, a deep well of lore, sharp controls, and terrific boss encounters. And so a sequel had a lot to live up to. But after seven long years of waiting, it’s finally here, in the form of Hollow Knight: Silksong. So in this video I’m going to investigate how Australian developer Team Cherry has put together this new world, and how they've thought about topics like progression, non linearity, navigation, back tracking, optional content, and more. There will be major spoilers for basically every inch of this game. There will be charts and graphs. And there will be hot takes about corpse running. I hope you’ll join me. I'm Mark Brown. This is Boss Keys. And this is the world design of Hollow Knight: Silksong. So, Hollow Knight: Silksong takes place in the withered kingdom of Pharloom - a twisty, maze-like land with 12 distinctly different areas: including a crumbling road made of bones, an industrialised forge, a gusty garden, and a farmland beset by eternal rainfall. And the game starts with a very clear goal. Hornet has been kidnapped, caged, and transported to this broken land. But with the help of a mysterious silken fly, she manages to escape. Now she can climb out of Moss Grotto - taking on her first boss along the way - and emerge in Bone Bottom, where she is given her first quest: To climb to the very top of Pharloom to find The Citadel, and track down the ones who tried to imprison her. Or in other words: go up. Yeah, it's a lot more to-the-point than the first Hollow Knight, where the protagonist has, essentially, ended up in Hallownest by accident, and just starts wandering around, looking for something to do. Your goal in Silksong, on the other hand, is super clear. Now in terms of progression, Silksong mirrors Hollow Knight 1 by starting with a pretty linear and guided trip through the first few areas of the game. After we emerge in Bone Bottom - our first town - we can journey through the Marrow, until we get our very first ability: the Silkspear. Well, it's technically not an ability, just one of a handful of different silk skills that we can use in combat - but, we do need it to blast through this web, so we can take on the Bell Beast. That's the second boss, but once defeated, it becomes our means of fast travel throughout Pharloom. Handy. With the Beast on our side, we'll then get safe passage to the Deep Docks, where we'll find ability number two: the Swift Step, aka the dash. This lets us hop over this gap so we can open up this gate, and then face another boss: the dainty swordfighter Lace. With her defeated - for now - it's off to the Far Fields. Here we'll meet the Seamstress who offers us a sort of side quest: basically, if we can gather up the spines that are shot out from these floating fleeces, she'll sew a new layer into Hornet's dress, which turns it into the Drifter's Cloak. This lets us catch these updraft winds and fly up to higher areas. On the way back we'll face boss number four: a giant, creaking metal automaton called the Fourth Chorus. With that thing dead we can ride the winds up, and up, and up... all the way to Greymoor. Here we'll face all manner of flying critters - including the fifth boss, Moorwing. This guy's a right pain in the butt. But, with Moorwing defeated, we've reached the town of Bellhart - but right now it's ensnared in giant webs of silk. So we'll pass straight through to Shellwood where, after a bit of climbing, we'll fight boss six - Sister Splinter. And with her defeated we can get another ability, the Cling Grip, which lets us climb up walls. Okay! Press pause. So far Silksong has proven to be a pretty straightforward game with a tightly plotted sequence of events. If we chart it out - this is Boss Keys, after all, we love a chart, we see a linear set of boss fights and new abilities. And if we lay this path over the world map, we see this: a giant U-bend through Pharloom, taking us, in turn, through Moss Grotto, Bone Bottom, The Marrow, Deep Docks, Far Fields, Greymoor, Bellhart, and Shellwood. It looks like the world's most simple metro map - without the usual zig-zagging and backtracking you'd see in other Metroidvanias. Of course, it doesn't feel so simple when you're on the ground. This is a game of winding pathways, and one-way doors, of enemy gauntlets and tricky platforming sections, of side rooms, elevators, chatty NPCs, and secret areas. So while you're in the thick of it, the game certainly feels labyrinthine and knotted. But, from a more zoomed-out perspective, the path is actually pretty straightforward. And here's why: For starters - if we think of an ability like a key, and the obstacles that ability helps you overcome as a lock - well, at this point each key only opens a few locks. Like, when you get the Drifter's Cloak... there's no point going back to the Deep Docks or The Marrow, or Bone Bottom because you won't get access to any new areas. And as for the lock that actually lets you make further progress through Pharloom? Well, it's always literally just around the corner from the key. Plus, there are only a few diversions you can make away from the intended route. For instance - from very early on, you can climb across these perilous hanging cages, and dodge this acidic barf, to enter an area called the Wormways. But, then again, almost all of the area is guarded behind a locked door, the only key we can get right now is from the shop in Bone Bottom and - 500 rosaries?! In this economy? You've gotta be kidding me. You can also mess around in the eastern side of Greymoor to find Craw Lake and unlock a new silk skill. And then the biggest diversion of the bunch is Hunter's March. But I'll come back to that later on. And finally - it's hard to ever get lost because you can always just use the ol' map-poking technique. Uh, sorry, that's a term I totally made up. But if you've played a few Metroidvania games you'll be familiar with map poking. It's when you open the map, look for paths and doors you haven't been through yet, and then methodically go to each one and see where you can make progress. And it's easy to do that in Silksong. The game has the same map system as Hollow Knight 1 - you start each area with no map at all, for that old school, Metroid 1, 'where the hell am I?' sensation. Until you find a cartographer - in this case, the warrior Shakra - who will sell you a map of that zone. Now you've got a scrappy, half-finished layout of the world. But when you next rest on a bench, the map will fill in with the areas you've visited. And crucially - you'll see open paths and passages to the areas you haven't visited. So if you're ever stuck, you can just poke at each unexplored area of the map until you make progress. You can also place markers on your map to remind you to come back to specific places later. So, so far, this is a pretty straightforward game. You're always moving forward through the map. Each key only has one or two locks, and the one that lets you make progress is always just around the corner. And the map gives you all the info you need to get going. But - once we get that Cling Grip, things change dramatically. Unlike before, this one key lets us open up a lot of different locks. And owning this ability suddenly opens up a bunch of new rooms and areas. So there are high-up areas all across Pharloom that we can now reach, letting us get to more goodies and items. We can even face new optional boss fights - like the charging Skull Tyrant in The Marrow. Also, once we have the Cling Grip - these guys will start to appear in a handful of locations. They're called Wardenflys. Little snotty jerks with big cages. And if they manage to trap Hornet, she'll be kidnapped, again, and whisked off to The Slab. This is a prison complex, high above Pharloom, where Hornet has no weapons or cloak until she tracks down her attackers. Now it's always a surprise in Metroidvanias when you're transported to some random corner of the map - like the teleporting chests in Elden Ring or the Snatcher in Bloodborne. For a genre that's so much about knowing where you are and where you're going, it's a big deal to suddenly be in completely unfamiliar territory. And so if you ARE taken to the Slab, you'll have to use the Bell Beast to fast travel back to Pharloom and carry on. Right. Let's get back to the actual progression. So, the Cling Grip lets us go to two very important places. For one, we can use it to climb to the upper area of Bellhart, and uncover the mystery of what has trapped this town - turns out, it's a fleet-footed weaver named Widow. And with her defeated, the spell is broken - reverting Bellhart to a normal town where we'll find NPCs, shops, side-quests, a needle upgrade, and more. Plus, we get the fifth upgrade in the game: the Needolin. This turns our needle into a musical instrument, which can be used to unlock a number of specific doors throughout the game. It's also essential for finishing this first act, but more on that in a second. The other important place to use the Cling Grip is to gain access to the next part of Pharloom - the Blasted Steps, which holds a perilous, wind-swept platforming obstacle course that will finally take us to the front door of the Citadel. Only... to find that it's, maybe, locked up tight. That's because it's jammed shut until we've rung five massive bells throughout Pharloom. You might have found and rung them already, or you might have missed some and have to go back and find them now. This is... a slightly strange quest. After triumphantly climbing all the way to the top of the Blasted Steps, you may find you are stopped at the very last moment and have to go all the way back down again. It's like getting to the top of a mountain and realising you left your camera at base camp. Luckily there's a fast travel point nearish to the summit. It's also a strange quest because finding these bells just isn't that tough - I mean, two of them, the ones in the Marrow and the Deep Docks, have to be rung to make progress through those areas, anyway. Another two, in Shellwood and Greymoor, can be missed if you're rushing, but they're not hard to find and aren't behind a boss or a platforming challenge or a puzzle. And then the final one is rung after defeating Widow and freeing Bellhart. Which might make you think that this bell quest ensures we've saved Bellhart before entering the Citadel. But... we need the Needolin, which we got from defeating Widow, to open the door anyway. Now it's not a bad quest, and it certainly ensures that you've explored a bunch of Pharloom before the next act. But it also feels like there could have been more to it. And, as it turns out, these bells may have had a different purpose during an earlier stage of development. So who knows. For now though, let's add them to the chart. Anyway! After ringing the bells, reaching the summit, and opening that gate, we face the hardest boss fight yet - and what might prove to be one of the hardest boss fights in the whole game - The Last Judge. She's the powerhouse guardian of the Citadel, who fights with flames, does two masks of damage upon impact, and can even kill you, right at the very end, with her final, dying explosion. Not cool, love. She is an extremely hard boss. Certainly a suitable cap to the end of Act 1. I had a lot of trouble with this fight, almost to the point of wanting to quit the game altogether. But, as it turns out... you don't have to fight The Last Judge at all. So I've just described Act 1 of Hollow Knight: Silksong as having a pretty straightforward and predictable structure. A sequence of bosses and abilities that must be fought and unlocked in a very specific order. And for most players, that is how they will scale Pharloom. It's certainly how I did it. But there are actually a bunch of ways to break that sequence, leave that intended path, and do things your own way. So, for starters - in The Marrow, you'll find the Flea Caravan. This works a lot like the Grubfather in Hollow Knight 1. You'll find fleas dotted around the world and when you get enough of them, you can go back to the caravan to get a reward. But unlike the Grubfather, the caravan will actually move to a new location on the map after you hunt down a certain number of fleas. From the Marrow to Greymoor after getting five of them. To the Blasted Steps after getting 12. And to the Pale Lake at the end of the Putrified Ducts after finding 22. And because the caravan site in Greymoor is literally in the boss fight room with Moorwing, well... if you manage to find 5 fleas before that boss fight, you can ride the caravan to that space and Moorwing simply won't appear in this room. Now it will appear later in the game in a different spot - but you won't have to fight it at all if you don't want to, turning this once mandatory boss fight into an optional encounter. Also - remember that expensive simple key from earlier? You know - in this economy? Well, 500 rosaries is a tall order at this early part of the game, but it's not impossible with a little grinding and farming. And purchasing this key lets you really throw a spanner in the works. For one, we can open this door in the Deep Docks. This lets us sneak through a bunch of rooms and pop out in the Far Fields - bypassing that boss fight with Lace entirely. Again, turning this essential encounter into a completely optional fight. Or, even better - we can go through THIS door in the Wormways. This lets us climb up to the top of Bone Bottom and enter Shellwood from the western side, meaning we've skipped Lace, the Drifter's Cloak, Fourth Chorus, and Moorwing. (Though, we will need to go get the Drifter's Cloak at some point as it's needed in Act 2). All of this stuff is totally intended and planned by the developers at Team Cherry, of course. Like, if you skip Lace by either method, she'll show up in a later location with a unique cutscene to tell you that she'll save the fight until later. But then there's the biggest skip of all. You see, among the many new places we can go with the Cling Grip, is Sinner's Road. This is a whole new area, off the northeastern corner of Greymoor, that's filled with nasty guard dogs, swinging traps, and pools of acidic goop that cover Hornet in a bile that slowly saps her silk. This place sucks. But within this area is another, even more hidden zone, called The Mist. It's one of those, you know, Lost Woods type of deals - a loopy, impossible maze where taking the wrong path will just whip you back around to the entrance. So you'll have to figure out that playing the Needolin will send these fireflies off towards the correct door. And if you successfully follow them a bunch of times you'll end up in an entirely new place called The Exhaust Organ. This is the home of another boss - Phantom, who is perhaps the closest to the Hornet fight in the original Hollow Knight. And defeating him not only unlocks another silk skill, ooo, a parry - but - surprise! - it also opens a path to the Citadel, and Act 2 - meaning you don't have to fight The Last Judge. That's right - there are two completely different ways to finish this act and enter the Citadel. There's the typical route through the Blasted Steps and past The Last Judge, and the more hidden route through Sinner's Road and past Phantom. And I like this a lot - because if you're struggling with The Last Judge (hello!), the game gives you an alternative route to tackle instead. One that's less about sheer boss fighting skills - I mean, Phantom is a lot easier than the Last Judge, and has less total health and does less damage with each hit. But is, instead, more about exploration, secret-hunting, puzzle solving, and survival. Plus, it just makes the world feel more complete and interesting. Of course there's not just one single entrance to the Citadel through some massive gate. There's also a sneaky side door by breaking in to its Underworks. And so here's the thing - when I first played through Silksong, taking that predictable path I showed in chapter one - I was ready to make this video and say that Act 1 is very linear. A strict sequence of events that must be followed exactly as Team Cherry intended. But it turns out there are sequence-shattering secrets all over Act 1 that let you tackle the game in all sorts of ways. Which is great. This offers different ways to play in future playthroughs. It rewards those who explore, or save up money, or find fleas. And while most players will take the quote-unquote normal path, it gives those who do stumble upon these alternative routes a very unique and special experience. And this doesn't even mention that you can also skip the Bell Beast, Sister Splinter, and Fourth Chorus... but with cheeky jumps and pogos, that are more like speed-running exploits than normal Metroidvania choices. So I won't go into them properly in this video. All of this means that Act 1 is perhaps more open-ended and non-linear than you might first think. With more optional bosses and alternative routes, and a more player-driven structure, than you initially realise. But if you think Act 1 is open, just wait for Act 2. Okay, now that we've made the pilgrimage up through Pharloom - however you ended up doing that - it's time to tackle The Citadel. This area is shown as just one big blob on the zoomed-out area map - alongside the Cradle and the Underworks - but, inside The Citadel, you'll realise that it's made up of a bunch of distinct areas. Well. Sort of distinct. To me, Pharloom - the land of Act 1 - very much feels like a bunch of different zones. Each one has its own colour palette and vibe and can be easily identified from a screenshot. But in the Citadel, the different areas feel slightly more same-y, and I felt like I was exploring one single space rather than lots of different areas. Though, I'll admit that each area does have its own ideas. The Cogwork Core is an industrial zone with spinning gears. The Whispering Vaults has box-shoving puzzles. The High Halls are all up-and-down elevators. And Whiteward is a small slice of a psychological horror game. Plus, there's some great environmental storytelling here - like how the enemies in the Choral Chambers carry loads of rosaries, but the worker drones in the Underworks have hardly any. And how the benches down here are pay-per use, showing how the staff are getting squeezed dry. So perhaps I'm talking my way out of this position. But still - as I reminisce on the game, I can't help but think of Pharloom as a bunch of distinct places and the Citadel as a single zone. Maybe it's like exploring a Metroid map, which then leads to a Castlevania map. Perhaps Pharloom is Zebes, and the Citadel is Dracula's Castle. That could work. The Citadel also feels - suitably - self contained and disconnected from all of the stuff we just did. For starters there are separate fast travel systems, with the Bell Beast in Pharloom, and pneumatic elevators in the Citadel - and only one connection between the two. So going back to the Act 1 areas has the extra step of getting to the Grand Bellway first. Plus, there's actually no reason to ever return to Pharloom once you've reached the Citadel. Now I'm sure you will for wishes, pick-ups, needle upgrades, and whatnot - but all of the upgrades, bosses, and paths forward through Act 2 are found exclusively within the Citadel and the Underworks. But the biggest difference between Acts 1 and 2 is in how progression works. Act 1, as we just explored, certainly offers variance - but that was by skipping and bypassing bits of an otherwise linear structure. Act 2, on the other hand, is completely open-ended by design. Okay, so both paths into the Citadel start in the Underworks. But once we've made our way through there we'll enter the actual building. A grand, opulent palace with stages, dining halls, and a spa. At the very top of the Choral Chambers is a boss fight against the Cogwork Dancers. Side note: what a brilliant boss. That's, like, an all-timer right there. But anyway. Beating these ballroom bots gives us a new quest. We need to collect three bits of a melody and then bring back the completed tune. These three song-lets are spread across the Citadel. And each one tests a different skill. The Conductor's Melody in High Halls is found after a frankly ridiculous enemy gauntlet with 10-or-so phases. The Architect's Melody in Cogwork Core requires serious platforming skills as you bounce over deadly gears. And the Vaultkeeper's Melody in the Whispering Vaults is behind a more traditional boss fight - against the theatrical ham, Trobbio. TROBBIO: Trobbio! Best of all, these three melodies can be found in any order. Lemme show you how. So, after we defeat the Cogwork Dancers, we enter the Cogwork Core. This gives us access to the Whispering Vaults where we can fight Trobbio - which, in turn, gives us access to the eastern side of the Underworks, where we find the Vaultkeeper's Melody. (It's actually just a cylinder, so we'll need to take it to Vaultkeeper Cardinius, also in the Vaults, to actually play it. But whatever). So that's the first part of the chart. Now, the other two areas with songs - the High Halls, and the upper part of Cogwork Core - are locked until we get the next ability. That would be the Clawline - a speedy hookshot-style ability, which can also latch on to hanging rings. This thing is in the Cauldron, on the east side of the Underworks. But there are actually two very different ways to reach it. For one, we can get to it after defeating Trobbio. We'll take this elevator down to the Cauldron and get the Clawline from there. Or, we can find the White Key in Songclave, use that to open Whiteward, work our way through, and then drop down into the Cauldron from that area. So... take your pick. Now, I love a Metroidvania upgrade that can be found through multiple routes. It gives players more agency, and it doubles their chance of finding it through exploration - or simply stumbling around. It also means that we don't have to fight Trobbio first, as he's not necessarily between you and the Clawline. And it means that it's actually possible to get to the High Halls, finish that tricky gauntlet, and meet Conductor Ballador before we've even defeated the Cogwork Dancers and gotten the quest to find the three songs. We'll just have to come back for the melody after the quest begins. So, you can hopefully see now that Act 2 is a very different beast to Act 1. Not only do you have three destinations, which can be completed in any order you like - but the whole business with the Clawline creates a tangled spaghetti mess. With the outcome being: how you finish this act is very much up to you. But you'll still unlikely to get lost. You can always rely on the map-poking technique I explained earlier. And the game even puts icons on your map to show you where the melodies are. They don't really spoil the game, if you ask me - they're just there to stop you getting completely lost, as you'll always know the general location of these all-important tunes. And so once you have all three pieces of the melody, that is, well, ultimately... the beginning of the end of the game. We can now take this elevator up, to the Cradle. Here we'll fight Lace - again, or for the first time, depending on what when down in Act 1. And then continue through the Cradle to face down the final boss of Hollow Knight: Silksong: Grand Mother Silk. Beat her. Roll credits. You're done. All of that gives us a final graph for Act 2 that looks something like this. I've simplified it a bit. But - in truth, this is not an accurate representation of playing the game. Not at all. Because we really have to talk about... So far, I've been talking almost exclusively about the main progression of Hollow Knight: Silksong. You know: the things you have to do to advance the story, finish the main quests, and get to the end of the game. But that is only a small part of what this game has to offer. Because here's the thing. In every Metroidvania, there's the stuff that you have to do to finish the game, and there's the optional stuff you can do that doesn't impact the progression either way. For instance, in Metroid Prime you'll need the high jump boots, the Varia suit, the boost ball, the missiles, and so on to overcome the obstacles between you and the final boss. But there are also energy tanks, missile upgrades, and even special weapons like the Wavebuster which all make Samus more capable, but they aren't required for any locks, bosses, or puzzles. So: totally optional. That means very Metroidvania has two piles: the mandatory pile and the optional pile. And in Hollow Knight: Silksong - well, the optional pile is massive. Like whopping. Like astronomically big. The amount of stuff you CAN do far outweighs the stuff you HAVE to do. I mean, to put it in numbers - there are 12 bosses that must be defeated before finishing the game. Moss Mother, Bell Beast, Lace, Fourth Chorus, Moorwing, Sister Splinter, Widow, The Last Judge - or Phantom, Cogwork Dancers, Trobbio, Lace - again - and Grand Mother Silk. And, yeah, that includes all the ones that can technically be skipped. But then are 17 more bosses on top of them. 17 beautifully drawn, designed, and developed baddies that are totally optional and do not stand between you and the end credits. 17 boss fights that you just might never come across. That's wild! Another way to think about it is in terms of items. All the goodies and pick-ups and bits and bobs you can stuff in Hornet's pockets. All of this stuff is optional - but just think how much crap there is in this game. There are 20 mask shards that increase your health, 18 spool fragments that boost your mana, 8 pouch upgrades, and 3 bottles of pale oil to increase the power of Hornet's needle. There are 6 different silk skills, which are powerful combat moves. Seven crests, which change Hornet's moveset and unlock special attacks. There are 20 red tools, which are sub weapons. 21 blue tools, which help in combat. And 12 yellow tools, which help with exploration. Plus 20 memory lockets, which let you equip more tools at the same time. There are also 3 silk hearts to improve mana regeneration, a charge attack move, endless bundles of the game's two currencies - rosary beads and shell shards, plus rare objects that can be sold to merchants for even more cash. There's craftmetal which can be used to make special tools. There are fleas, simple keys, and bags of frozen peas. There's so much stuff. Some of these things are simple upgrades that give you more health, mana, ammo, and money. But others completely change the game - giving you a chance to make a totally unique build that works for you and the way you like to play. It is a lot. And all of this stuff is going to be useful because Silksong is, famously, a very hard game. A game with gruelling boss fights, exhausting enemy gauntlets, and difficult obstacle courses. Now Team Cherry knows this - but has always said that the solution to getting stuck in a Hollow Knight game is to just... go somewhere else. To stop beating your head against a brick wall and instead try another route. Ari Gibson says that players who get stuck “have ways to mitigate the difficulty via exploration, or learning, or even circumventing the challenge entirely, rather than getting stonewalled". So, as Ari said, sometimes that means skipping the fight through a cheeky secret path. Other times, that means finding someone to help. For instance, you can find Garmond and Zaza in a side room in Greymoor, and get them to assist in the fight with Moorwing. But the most obvious way to help improve your chances is to find some of these optional items and goodies. Some extra health or a tool that speeds up healing can be the difference between success and failure. Though - I do want to note that this intention, for players to go somewhere else if they get stuck, is largely undercut by Silksong's use of corpse running. That's a gameplay system where - when you die, you'll lose some of your stuff. Specifically: all of your loose rosaries - the game's main currency. And also any spool upgrades you've found. So you'll need to go back to the place you died and smack your cocoon to get your stuff back. This idea was popularised by Dark Souls, and then borrowed for Hollow Knight. And the idea is once you've died, you're in a heightened state of play because you're less strong - and if you die again before getting back to your corpse... you'll lose your stuff for good. So it can be a good tool for amping up the stakes. But I just don't think it works for a Metroidvania. We want players to die... and then go explore somewhere else instead. But the corpse running system just encourages them to keep going back to the same place, over and over again. Now, Silksong does have some ways to reduce its impact - like these tools that turn loose rosary beards, that are lost on death, into strings of beads, which aren't. And the Silkeater item gives you a few chances to retrieve your corpse. But overall - I just don't think this is a good system for this sort of game. I didn't like it in Hollow Knight, I didn't like it in Elden Ring, I don't like it here, either. But, okay, another thing worth noting is how many items you can possibly find before each boss fight. For instance - in terms of mask shards, there are 20 total in the game, meaning you can double your health with 5 additional masks. But the vast majority of them can only be found in Act 2. And that's true of almost every other pick-up, too. So if we consider the bosses at the ends of Act 1 and 2, The Last Judge and Lace. Ignoring Phantom for now. Well, before fighting The Last Judge we can theoretically find 6 mask shards, (which gives 1 extra mask) 6 spool fragments, 1 needle upgrade, and about 25 tools. And considering that the Last Judge does two masks of damage with every hit, one extra mask doesn't help all that much. But then before fighting Lace, we can find 10 more mask shards, adding 4 more masks, 12 more spool fragments, 2 more needle upgrades, and almost every tool in Silksong. That makes a big difference. Like, there's just not a huge amount of stuff we can do to improve our chances against The Last Judge - the biggest one being this magma bell that nerfs incoming fire damage - but when it comes to Lace, well an industrious player can massively tip the fight in their favour. And so I think this is why I found Act 2 to be almost easier than Act 1. In the first act I felt like I had to just constantly retry boss fights like Moorwing, the Fourth Chorus, and The Last Judge. There wasn't much else I could do. But in Act 2, if I was struggling with Trobbio or Lace or Grand Mother Silk I could just go somewhere else, get more power, and come back later. But okay. With those caveats aside, let's ask the question: where you do find all this stuff? Okay, so we've established that Silksong has a buttload of optional stuff to find. But the important question, in terms of Boss Keys, is asking how players will discover them. And well, ultimately, there are four main sources for finding optional items in the game - backtracking, secret walls, shops, and wishes. Let's start with backtracking. For the main progression, Silksong almost never asks you to go back on yourself. Act 1 can be finished through endless forward progression. And Act 2 is entirely self contained - with everything you need to complete that quest being found exclusively within the Citadel and the Underworks. That's a bit unusual for a Metroidvania, where part of the joy of the genre is zig-zagging back and forth across the entire map. Perhaps unlocking a new ability in one place and then going all the way back to the very start of the game in order to use it. Silksong doesn't really do this for its main path. But it does have stuff for those who return to a previous zone with a new ability in tow - it's just almost always optional. For instance, there's a path off of the Marrow with a big beefy baddy who will promptly turn you into mashed potato. It's teaching you, very early on, that sometimes you'll want to leave and come back later. So if you return after getting the dash you can outfox this guy, defeat him, and enter a whole new area: Hunter's March, which holds a flea and a secret shop. And if you come back with the Drifter's Cloak, you can fly up here... in order to face the Savage Beastfly and - if you manage to defeat that - unlock the powerful Hunter's Crest. And this happens throughout Silksong. Each time you get a new ability you can use it NEARBY to move forward and make more progress. OR you can turn around, go back to somewhere you've already visited, and use the ability to unlock something cool. The Clawline is a particularly good example, actually. Technically, it's only needed within the Citadel - to open the paths to High Halls and the Cogwork Core, in order to get parts of the Threefold Melody. But we can also backtrack to the zones we visited in Act 1, and use it to unlock a bunch of new places in Pharloom - including a whole new area called the Sands of Karak, a new part of the Deep Docks, plus a mask shard back in Far Fields. Oh! And it can also be used in the Slab to reach another whole new zone: Mount Fay. This is an icy alpine area on the western edge of the kingdom. It's so cold that Hornet will take damage if you've been exposed to the elements for more than a few seconds. So you'll need to dash between these heating lights to stay warm, and reset the countdown. At the very top of the mountain is, actually, another upgrade - the Faydown Cloak. This fuzzy winter coat not only protects you from the freezing temperatures, but also gives you a double jump. And seeing as I've only just mentioned it, after talking about how to finish the game, you'll hopefully realise that this thing is - again - optional. I mean, if you do find it while playing Act 2 then it will certainly come in handy. It will make the Cogwork Core platforming section a lot, lot easier. And you can also use it to find a secret area in the High Halls, where you can stop these silk-sucking marionettes from ever appearing throughout the Citadel - which will help out during that ridiculously long gauntlet. But, still, the Faydown Cloak is not technically essential and you can finish the game without it. But, again, with this thing under your belt you can now backtrack across the map and use this new power-up to find a whole bunch of new areas across both Pharloom and the Citadel. Like Wisp Thicket, which is above Greymoor, and Memorium, which is at the top of the Citadel. There are new optional bosses like The First Sinner, Father of the Flame, and Voltvyrm - all of which drop powerful silk skills and tools. And there are lots of useful goodies to find. So - the point is, Silksong almost never asks you to backtrack - but if you do it, you'll be rewarded with all sorts of helpful items. And I think this approach to backtracking works really well. It means casual players can just stick to the main quest and make progress by always moving forward. But it also means that Metroidvania obsessives still get a big advantage for, you know, committing the world map to memory, and being super fastidious about exploration. Okay, so that's backtracking. The other way to get these optional items is through secret walls. All across Silksong are these crumbling walls that you can break open. Or they're sometimes just cheeky passageways that are covered up by bits of the foreground. These things defy map poking because, until you find them, they do not show up on your map at all. It looks like you've explored the whole space - but, ahh, no you haven't. Now these things are everywhere - I counted more than 50 across the map on my second playthrough for Boss Keys. And they hide items, boss fights, shops, and even entire areas. Seriously - both Bilewater and the Putrified Ducts are hidden behind secret walls, and so it's entirely possible to play the entire game without ever knowing these places are there. Seriously - I beat the whole game without stepping foot in Bilewater. The only clue was that suspicious empty space on my map. Though, it should be noted that you are given some help with finding these locations. Bilewater can be discovered through two different hidden walls - in Sinner's Road and in the Whispering Vaults, meaning you've got two chances to find it. Meanwhile, there's a side-quest where you track the shopkeeper Jubilana - which shows a trail through a secret passageway in Memorium, and takes you to a hidden area above Songclave. From there, it shouldn't be too hard to find this breakable wall that leads to the Putrified Ducts. We can also get optional items from shops. That one's pretty self explanatory. There are shopkeepers across Pharloom and the Citadel, and each one will sell tools, spool fragments, mask shards, and more in exchange for rosary beads. So if backtracking and secret walls reward exploration, then these shops reward being economical with money, and not losing your cocoon - and the rosary beads you were carrying - by dying a lot. And then there are wishes. These are side quests that can be picked up from bulletin boards in the major towns, or by talking to specific characters. Many of these are simple quests that you'd see in other games. You know: kill specific enemies and gather their spoils. Track down an NPC by following their trail. Find materials. That sort of thing. But there are more notable ones too. There are wishes with special boss fights, like the Skull Tyrant in the Marrow and the Broodmother in the Slab. And there's the wish Great Taste of Pharloom, where you need to find four ingredients across the entire map of Silksong, and deliver a rasher from Bellhart to the Citadel without it disintegrating - all of which gives you the necessary item to boost your needle's power. Oh, and there are also other side activities that aren't listed as specific wishes. Like in the Citadel, you can find three cogheart pieces - which then go together to power up this robot sentinel. And so between the cogheart pieces, the taste of Pharloom, and the threefold melody - you could be doing three completely different "find all of these objects" quests, simultaneously, throughout Act 2. Overall, I think side quests fit really well in a Metroidvania. It's not typically a part of the genre - I can only think of a few examples with them, like Prince of Persia and some of the Castlevania entries on DS. But they make sense. They give you something else to do if you're lost or banging your head against a boss fight. They often give you a reason to revisit an area you've long forgotten about. And they reward other types of activities like scouring the map, or collecting things. So - Silksong is jam packed with optional goodies to find. And as I said in the previous section - they'll prove very helpful in a game this difficult. But this stuff actually has a much bigger impact than just letting players modulate the difficulty. Because the real side effect of having so much optional stuff is that it makes the adventure inherently less linear. At almost every moment in Silksong, you can make a choice about where to go and what to do. You could follow the main quest progression - or you could go and work on a wish, or explore some new area of the map, or backtrack to an old place with a new ability, or retry that boss you skipped earlier, and so on, and so on. And this makes each player's experience way more personal. The areas you visit, the bosses you fight, the secret walls you uncover, the wishes you find and complete, the crests and silk skills and tools you find and use... all of this changes from player to player. Which ones will you encounter, and what order will you discover them? By having so much stuff be entirely optional, it means that each playthrough of Silksong is unique - and not at all defined by the developers. But. With all of that being said. Perhaps I'm being a bit hasty to describe all of this stuff as being truly optional. Because, as it turns out, a lot of this stuff ends up being way more important than I've first let on. Okay, so you might have felt like the final boss fight was a bit easy. And that the final cutscene before the credits was a tad bleak. Like... this can't be the real ending of the game, can it? And you'd be right. Just like Hollow Knight 1, there's a lot more to do if you want to see this thing through and unlock the true, final ending. This all comes in the form of a wish, Silk and Soul, which is given by the Caretaker in Songclave. This quest will kick off a sequence of events that will lead to the real ending of Silksong. But actually getting wish thing to appear means fulfilling a hodgepodge collection of prerequisites and requirements. Including... a whole bunch of specific wishes, many involving big donations of rosaries and shards to wish walls. That also includes the wish Trail's End, which involves buying all of Shakra's maps - meaning you'll need to have been to all the major areas in the game. You'll need the Faydown Cloak from Mount Fay. You'll need the Bellhome key, which you get from doing wishes in Bellhart. You need to move the Flea caravan to Fleatopia - which means finding the Pale Lake and hunting down 22 fleas. And you'll need 17 "quest points", which come from completing miscellaneous wishes. Now this list is not actually in the game. You can of course find it on Wikis and Reddits and whatnot. But inside the game itself - well, I guess it's supposed to just be a thing that will trigger when you've proven that you've done a lot of the game. Lore wise, I think it's supposed to show that Hornet truly cares for the people of Pharloom, and has shown this through charity, effort, and bravery. Which is very cute. But because it has so many specific prerequisites - like the Bellhome key and that one wish with Shakra's mentor - well, a lot of players may not trigger it, and just want to know how to continue with the game. I mean, it's quite telling that the first results on Google for "Silksong how" are all about unlocking Act 3. So perhaps there could have been another, less obtuse, way to have this thing unlock. But okay. Once we have this quest, the Caretaker has a plan to defeat Grand Mother Silk without plunging Pharloom into chaos. We just need to gather up four items. We need to get the Maiden's Soul from the Chapel Maid in Bone Bottom, and the Hermit's Soul from the Bell Hermit in Bellhart. Both of those are just about asking nicely. The Seeker's Soul is a lot tougher because we have to defeat Groal the Great in Bilewater, which is perhaps the worst boss in perhaps the worst area. Joy. And then finally, we need the Snare Setter item, which can be found in Weavenest Atla, back at the very beginning of the game. What's interesting is that three of the four items needed are behind hidden walls, or in hidden areas. And as I explained earlier, these things aren't shown on your map and so can't be discovered through simple map poking. And on top of that - this is where Silksong finally makes backtracking part of the main progression. We'll need to return to Bone Bottom, to Moss Grotto, and to Bellhart in order to grab items that weren't available on our first trip there. Basically: now that casual players have seen the ending and left somewhat satisfied - Team Cherry can amp up the challenge for us sickos who want more. Not just the difficulty of the bosses, mind you - but the difficulty of the exploration and navigation. Though, it should be noted that the Caretaker will at least give you clues for each part of the quest in his dialogue. So that's Silk and Soul - it adds another dose of non-linear exploration to the game. And with the Soul Snare finished, we can fight Grand Mother Silk again - but, this time, we'll play the Needolin at the end. This gives us a very different ending cutscene. And if we load up the game again, uhhh, our save file looks rather strange. Let's load it up. Welcome to act three. Now there's a bit in Hollow Knight 1 where the familiar Forgotten Crossroads area has become corrupted. Useful pathways are shut off, and basic enemies have mutated into more powerful forms. Well, this is the premise of Silksong's third act - only it covers the entire map. Entire areas are damaged and destroyed, there are broken pathways, and enemies have a chance of being corrupted by the void - which makes them more deadly and resilient. It's a case of reimagining a place that you thought you had come to know well. A twist on the familiar. Kinda like the upside down castle at the end of Symphony of the Night. And for the first big twist - when we go to use the Bell Beast to fast travel back to Bone Bottom, we'll find that it has been usurped by the Bell Eater - our first new boss of Act 3. Killing that pooping weirdo gives us back the Bell Beast, plus a handy new ability. We can now use the Needolin to call out for the Bell Beast's kids - which warps us back to the nearest fast travel point. Now I'm always a fan of holding back quality of life stuff until the back part of the game. You wouldn't want to have this throughout the whole of Silksong - it would make things too easy. But now we're in the final stretch, it's nice to remove some of that tedium. Anyway - while it's nice to have the Bell Beast back, I think it would have been fun to have to walk all the way back to Bone Bottom on foot, rather than just fast travelling there. It would have been a good way to see how both the Citadel and Pharloom have changed for Act 3, it would give you a bunch of new combat challenges on the way there, and it would be a clever twist on the goal of the first two acts - to descend, rather than to climb. Whatever the case, once we're back at Bone Bottom we find the Shamans, who give us a quest to dive deep beneath Pharloom, into the Abyss. (I guess that's the twist on the Act 1 goal - to reach the lowest part of the map, rather than the highest. Fine. Whatever. Ignore me). So it's time to go back to the Deep Docks, where there's a diving bell. Now we might have already found this thing in Act 2 - it's just sitting there, behind a Clawline ring and a boss fight against the Forebrothers Signis and Gron. In fact - that might be for the best as the boss encounter is actually harder if playing in Act 3, thanks to the addition of mutated enemies. Whatever the case - we take the diving bell down. Deep down. Very deep down. Into the abyss. This is a slightly more linear section, and also the location of the game's final ability: the Silk Soar. This lets us fly up vertically. It's useful for getting to areas that are too high for even the double jump - and it's a bit like the Shinespark in Metroid, but without the run up. We can also use this new move to leave the abyss in a thrilling escape sequence. Which is also quite Metroid coded, let's be honest. Now we're back in Pharloom, we can use the Silk Soar to finally reach every single area on the map. Nothing is off limits now. And we can use it to backtrack to various areas and unlock a number of optional goodies. That includes a mask shard on Mount Fay, a silk skill in the cradle, a new quest involving Mr Mushroom in Pale Lake, and an optional boss fight against the Watcher at the Edge in the Sands of Karak. Who drops a completely useless memento. Great. Cheers. What was the point of that? But our actual goal is to go back to Bone Bottom and get the real quest of Act 3. That quest is to gather three hearts by tracking down dead or otherwise defeated warriors - and then using a new Needolin song to pop into their memories. There we can defeat them and win their heart. Those hearts are... The Heart of Might. This comes from Crust King Khann in the Coral Tower at the top of the Sands of Karak, past two boss fights against giant Conchflies. Again, like with the diving bell, we might have already been here in Act 2. But either way, we can now use the Needolin to enter Khann's memories, fight through several tricky gauntlets, and then take down Khann himself. Then there's the Heart of Pollen. This one will take us back to the elevator shaft that goes from the Grand Gate to the Underworks. And by using Silk Soar we can leap up to this higher section. That leads us to two bosses in a row - Shrine Guardian Seth (rest in peace) and then Nyleth. This is a tricky platforming-focused fight that will have you bouncing back and forth from wall to wall, over a pit of spikes. And finally there's the Heart of Wild. For this one we can go back to Hunter's March and use the Silk Soar to jump over this statue. This takes us to a new part of the Far Fields and eventually, to a showdown with the operatic Skarrsinger Karmelita. One of the hardest bosses in the game. Like in Act 2, the locations of these bosses are put onto your map as icons - to help you track them down. But because this is Act 3, the actual entrances to these boss areas are often hidden, and thus not shown on the map. The paths to Nyleth and Karmelita are behind secret walls - and so they're immune to map poking. But - like Act 1, there is also another way to complete the quest. You see, there's actually a secret fourth heart. If you saved the Green Prince from his cage in Sinner's Road, using a simple key, you can find him in Greymoor. Here you can enter his memories to find an entirely new zone, Verdania, and fight the Clover Dancers - a clever storytelling callback to the Cogwork Dancers in the Citadel. Defeating the Clover Dancers gives us the Conjoined Heart which can be used in place of another of the other three - useful if you can't find the entrance to Nyleth's shrine, or you suck too much to beat Karmelita. Hello! So, those are the four hearts we can find. But we only need three of them, at which point we can take them back to the Shamans to kickstart the ending of the game. We'll go through Hornet's memories to get the Everbloom. Then return to the Abyss and fight the real, actual, promise this is the final boss - Lost Lace, before seeing the true ending of the game. All of which means Act 3 looks something like this... with a few steps being completable in Act 2 if you were being particularly thorough. Like Act 2, this final act is non-linear and free-form - guided by the player's decisions and abilities. Oh, and before I wrap up this section - it does mean I'll need to recalculate that previous claim that there are more optional bosses than mandatory ones in Silksong. So, at the end of Act 2 there were 12 mandatory bosses and 17 optional ones. We'll need to promote the Great Conchflies, Groal the Great, and the Forebrothers to mandatory, as they're part of the progression through Trail's End, Silk and Soul, and Act 3. If we ignore Khann and go after the Clover Dancers, we'll need to add Seth, Nyleth, Karmelita, Clover Dancers, and Lost Lace as mandatory fights. It's not looking good... But! There are loads of optional bosses in Act 3, including a fight with the Pinstress, an annoying chase after a mythical Palestag in Verdania, and a rematch with a tormented Trobbio. TORMENTED TROBBIO: Trobbio!! Which all, to my count, means there are 20 mandatory bosses in Silksong, but 25 optional ones. My point still stands! The video still works! Okay, let's bring this all together. When we consider the entire game, Silksong has a very interesting structure. Act 1 has this tightly paced, pretty linear progression, with a non-stop parade of boss fights, upgrades, and new areas. But then Act 2 is more loose and freeform - a non-linear sequence where you're free to wander and explore in a more meandering fashion. And then Act 3 is a mix of the two - with linear sections like the Abyss, and then exploratory parts like finding the three hearts. This concertina structure, which dramatically bounces between moments of forward propulsion and slower discovery, keeps the game interesting. It's a constant change of pace that means Silksong never sings on the same note for long enough to get boring. On top of that, the game constantly offers ways for players to break and bend the obvious structure of the game. Act 1 is full of cheeky skips and sequence breaks. Act 2 has the stuff with the Clawline. And Act 3 lets you pick 3 hearts from a total of 4. This gives players more agency, it makes each playthrough different, and it gives options for speed-runners and challenge players to tackle the game in a different way. And then on top of that, there's just endless optional content to complete. Wishes, bosses, pick-ups, and secret areas. This makes each playthrough completely unique. It lets you modulate the difficulty of the game - by giving you a way to turn the tables against bosses. And it lets Team Cherry keep the golden path through the game quite simple and straightforward - but provide lots of rewards for the players who explore, who save up money, who poke at suspicious walls, and who backtrack to earlier parts of the game. And then on top of all of THAT, this is a world that feels coherent and cohesive. This is not just a bunch of arbitrary zones stitched together for the sake of a Metroidvania. But the world layout makes sense. Each location has a reason for being - and a reason for being where it is. And ultimately the grand story of the game - about this pilgrimage from the depths of Pharloom to the heights of the Citadel - is represented on the world map itself. The level design and the way you transport through it tells the story just as clearly as any lore dump. Put all of this together. A changing pace. Alternative paths. Optional goodies. Coherent storytelling. Put all of this together and we get a Metroidvania made with such obvious skill and thought - taking it to the highest echelons of the genre, and making it the new gold standard for other developers to aspire to. Hey! Thanks for watching. And thanks for watching all my stuff in 2025. This is my last video of the year because I am just about to go on paternity leave! Yeah, that's right - I'm gonna be a dad! Get your "Baby Maker's Toolkit" jokes out of your system now. I'm taking a few months away from YouTube to really enjoy this time so I won't be around for a bit - but I hope you'll still be here when I get back! Thanks so much.