The World Design of Super Metroid | Boss Keys

In 1986, Nintendo released Metroid on the NES. It was nothing like the company’s other games: it wasn’t cute and colourful and full of chirpy music. It was dark, and atmospheric. Bounty hunter Samus Aran felt truly lost and alone as she explored an endless sprawl of dank, alien corridors. And it was fascinating. But it was flawed. It was way too easy to get lost, the world all looked the same, and many secrets were hidden behind brick walls.

It was the start of something cool, but it needed refinement. The sequel, 1991’s Metroid II: Return of Samus on the Game Boy, didn’t really help matters. It was still dark and scary - and it had a surprisingly impactful ending for such a formative game. But the monochrome screen made it even harder to find your way around - despite the fact that the game is much more linear than the first one. We’d have to wait a few more years for the real deal.

And then we got it. In 1994, Nintendo released Super Metroid, on the Super Nintendo. Finally, the idea behind Metroid was given the proper execution. The game, once again, dropped Samus into a lonely, alien world - the same planet Zebes as Metroid 1 - but this time, you could actually get around without drawing a map, bombing every wall, or buying an issue of Nintendo Power. The structure of the game is much the same: just like Metroid 1, this game is about making a mental note of obstacles.

Then finding items. And then backtracking to those obstacles to either find goodies or the next bit of the game. But this time, things are different. The world is much bigger. The power-ups are more interesting. The bosses are more varied. And the designers take a much more active role in getting you through Zebes - just, with far more subtlety than Metroid 1’s overbearing remake, Zero Mission. How did they do it? Well, really, the only way to properly describe how the game does this is to take you through it, step by step.

Which is exactly what I’m going to do in this video. Let’s touch down on planet Zebes, once again, and start the second episode of Boss Keys, Season Two.

Just like Metroid 1, this game wordlessly explains its set up in the first few screens. In the very first corridor of Zebes, we walk past a bunch of doors that we can’t get through. Pink doors that bounce away our bullets, and tiny gaps we can’t squeeze through. Eventually, we’ll find the entrance to Old Brinstar - which is actually the final and starting areas of Metroid 1. And here, we’ll grab the Morph Ball and Missiles.

With no where to go, we can only go back to where we came from. But now, these areas are teeming with space pirates, letting us know that this is actually the right way to go. So in the first few screens, Super Metroid says: this world will branch out at every point but many of those routes will be inaccessible until you have more powers. And oftentimes, the path forward will actually be behind you. So, we use those missiles to grab the bombs and - woah!

Heh, a good reminder that you can’t rely on expectations in this game. Now, with the Torizo dead, it’s time to use these bombs to explore further. And if you don’t know where to use them, you’ll soon learn about the virtues of the map - oh yeah, Super Metroid finally adds a map screen to the franchise. And map terminals. You’ll find map terminals in the game’s five major locations - Crateria, Brinstar, Norfair, Maridia, and the Wrecked Ship - which reveal some of the rooms around you on the map.

Handy, when it shows you rooms that are hidden away behind brick walls. That makes finding map rooms almost as useful as finding a new power-up - and is one example of how Super Metroid is way more player friendly than the obtuse Metroid 1 - but without being quite so aggressively hand-holding as Zero Mission. The newly updated map screen shows a room over to the left - giving you the hint to use your bombs and keep going.

Here, we’ll find the last point of interest in Crateria. At the far end of an ominous tunnel is a great golden statue depicting four bizarre monsters - one of which we faced in the game’s prologue. I’m sure we’ll be coming back to that, later. For now though, let’s hop onto the elevator and make our way down to Upper Brinstar.

So. Let’s take a break to map out the structure of Super Metroid, at this early point. And to do this, we can use a dependency chart - which is something I came up with during the first season of Boss Keys. On this chart, diamonds represent upgrades that Samus can use, and squares represent the obstacles that she can overcome with those upgrades. For this chart, I’m also using triangles to represent non-essential pick-ups like missile tanks and the map room.

Not every single pick-up, mind you: just the ones that can be found with simple exploration, or are found behind obvious locked doors and obstacles. So these upgrades, locks, and pick-ups cascade down from this horizontal line, which represents all the places we can visit right now. And the locks go below the upgrades. I’ve also put on some locks we can see, but can’t overcome - like some high up areas in Crateria, that will need the space jump.

And a green door, which requires Super Missiles. I’m going to use dotted lines, until we can actually reach this stuff. So here’s what the graph looks like at the moment. So far, pretty simple. Let’s move on. When we get into Brinstar, we’ll find a lot of dead ends. A room that we’re too slow to travel through. Some weird symbols on the ceiling. A yellow door, which won’t budge. A green one, much the same. And blocks that don’t blow up when bombed - but instead show us an icon of some power-up that we’ll need to attain if we want to break through.

There’s lots to explore here - but it’s all dead ends. A stark message that we’re not strong enough yet, and a reminder that we’ll have to come back here later. We can do two things, however. We can fight the first mini-boss in the game, Spore Spawn, and get the Super Missile. And we can get the Charge Beam. That’s hidden down here. Well, I say hidden: the game has two very obviously different blocks, and the slight hint of a ceiling.

Throughout Super Metroid, hidden areas like this are pretty well telegraphed, with plenty of hints. There’s hardly any random bombing, like Metroid 1. The charge beam is also one of many items in Super Metroid that are completely optional: extra weapons like the charge beam, spazer and plasma beam, handy upgrades like the spring ball, and the very useful x-ray beam - which makes it even easier to spot hidden walls - are not needed to finish the game at all.

Their existence is great though, as they can be found at any time, making the game less linear. And they feel like genuine secrets that other players might completely miss. Let’s update our graph again. So we’ve got lots of dead ends, and only a few things we can actually do. For now, Super Metroid is staying quite simple. After you open that green door with a well-placed super missile, you’ll come into this room. You’ll shoot this blue button to open this gate, and exit to the next room.

What you may not have realised, though, is that the gate shuts behind you, and it’s impossible to hit the blue button with your current tool set. You’ve just completely cut off access to everything in the game before this point. This is for two very important reasons. One is that the next room requires you to use a skill you might not even know you have: the run. And Nintendo doesn’t want you to think you don’t have the necessary upgrade to get through this room and have you wander back, trying to find some alternate route.

No, you’re stuck here until you figure it out. Read the manual, maybe. The other important reason? Well, soon after this room, the same thing happens again. You’ll fall down this shaft and you can’t get back up. Again, there’s no access to the world behind you. All that stuff in Brinstar, with the yellow doors and the funny symbols and breakaway floors? You can’t get there anymore. And in this way, I think Super Metroid tries to avoid overwhelming you with options.

Remember that gripe from Metroid 1, where you have so much access to the world that finding the way forward is dizzying? Not so much here. Because the world closes off behind you, you only ever have a small chunk of Zebes to explore at once.

Right. We’re in Lower Brinstar now. And, first, you might notice that the map screen has another treat for you: a secret room, just to the right of this elevator. Unfortunately, once you’re inside, you’ll realise that you can’t jump up here yet. But look at that spooky face. That’s definitely worth checking out, when you’re skilled enough. This is a classic example of using a really distinct visual as a landmark, to cement it in your brain and help you remember to come back once you’ve got the right gear.

The same thing happens with Ridley’s lair, sort of. And definitely with the entrance to Tourian. For now, though, the only other place you can go is down, into Norfair. Here, you’ll find more dead ends - like a room that you’re too slow to run through, and a room too hot to be in. And you’ll also find another power-up: the hi jump boots. Oh hey, now you can go back up here, kill the first boss - Kraid - and get the heatproof Varia Suit.

Yes, that’s just how I pronounce it now. Oh hey, now you can go back to that superheated room, and get the speed booster. Oh hey, now you can get through that first room, and get the Ice Beam. By bouncing you back and forth between Norfair and Lower Brinstar, Super Metroid is training you to know that your goal isn’t always in the immediate vicinity, like it was earlier in the game. Sometimes you’ll have to backtrack a fair bit, to a previous zone even, to find the next step forward.

It’s graph time, again! So here’s Lower Brinstar and Norfair. You might remember that there are some obstacles back in Upper Brinstar that we could now overcome with our new items, like the speed booster, but - remember - they’re up an impossibly high shaft, and behind a one-way door. We just can’t get to them, meaning that they stay as dotted lines on our graph. Once again, Super Metroid is reasonably straightforward in its structure, and pretty compact in its world size.

But here’s the thing: Super Metroid is a game that will hold your hand tight, when it wants to. And let it free, when it wants to. And at the beginning, the game holds a pretty firm grip: this early part of the game keeps you stuck in a very small location, and uses one-way paths to keep you locked into just a handful of rooms at once. And with each power-up you get, there’s a very limited number of places to actually use it.

After you get the Varia Suit, there’s only one superheated room to explore. After you get the speed booster, there’s only one room where you can use it. After you get the bombs and super missiles, there’s just a couple obstacles that you can now overcome. And so on. If Super Metroid kept up like this, I think it would grow tiresome and be way too easy. But that’s not the case. Because, now, this is the moment that Super Metroid shifts.

So you’ve just got the ice beam. And almost every time you get a power-up in Super Metroid, you’ll be trapped until you use that power-up to get back out, giving you a handy tutorial on how to use it. But, also, that room will give you hints about where that power-up can be used next. Like, after getting the ice beam you’ll need to freeze this enemy to get out. And where else have you seen these enemies? Oh yeah, right here on that shaft you fell down into Norfair.

So now, you can get back up, use your hi-jump to hop up here, and grab the power bomb. And it’s here that Nintendo lets go of your hand. if you follow the path forward, you’ll head up here, jump off this ledge, and realise that - hey, you’re back at the start of the game! You just did a full circle of Zebes. But things are very different now. The spooky, ambient music… has been replaced with a bombastic, heroic tune….

Samus is now kitted out in her iconic orange varia suit. And the path forward is… uh, well, I don’t know. Because at this point, you can now explore a huge amount of Zebes - including all those old areas that were previously locked off by one-way paths. And there’s a massive number of obstacles you can now overcome. By my count, there are about seven places you can power bomb, two places you can use your speed booster, and one place you can use your high jump.

And none of them are calling out to you as the obvious next step. So after a very straightforward and somewhat guided route through the game, Super Metroid says it’s now time to explore for yourself. Sometimes you’ll find handy upgrade. Like, remember this speed booster room in Brinstar? You can now go in there and get a reserve tank. Sometimes you’ll find dead ends, like a room where you won’t be able to advance without the grapple beam.

Sometimes you’ll find some weird animals - more on them, later. And eventually, you’ll find the path forward - it’s actually down here, in Norfair. I really like this. Remember that end game item hunt from Zero Mission? It was fun, but kind of awkward: you basically leave the intended path at the very end of the game and take a huge detour to do a victory lap of Zebes. but in Super Metroid it’s slap bang in the middle of the game.

You don’t know where to go, so you just have a wander and see what you can find. The game takes a break from linearity, to let you just explore for a while. And then there’s that sensation of simply stumbling upon the next area. That’s a really potent feeling that some Metroidvanias do well - this feeling of organically discovering some massive new area filled with unseen stuff. It’s a feeling we’ve seen in previous episodes of Boss Keys, and it’s a sensation that we’ll definitely come back to in a future episode of this season.

Oh, and during this exploration of Zebes you might revisit this room and find that one of the statues has turned grey - reminding your that your ultimate goal is to kill four bosses - well, three now - and then come back here to finish the game.

The next step is to kill Crocomire, who has the most metal death in all of video games, and get the grappling hook. This is a really fun item to use. And the game has a really nice loop in the level design, after you get it: instead of asking you to just boringly backtrack to the start of the area, there’s a whole bunch of rooms that bend back on themselves and bring you right back to the elevator in Norfair. From here, Super Metroid again asks you to explore.

There are about seven spots where you can use the grappling hook, and they’re dotted all over Zebes. Some lead you to new power-ups like the wave beam, and x-ray beam. Others lead you to upgrades like missiles and energy tanks. And one leads you to the wrecked ship, where you’ll continue your adventure.

Here, you’ll face the second boss of the game: Phantoon. And after this, Super Metroid starts getting a bit cheeky, and introduces more of those obtuse brick walls from Metroid 1. Like, to get to the gravity suit, you need to bomb through here. To get through maridia, you need to get into this little hole. And to get into Maridia proper, you need to drop a power bomb in this glass tube. To be fair, all of these things are telegraphed.

Before getting the gravity suit you can see a room here, so it’s a case of looking for some way of getting in there. You can see enemies coming out of this hole, letting you know it exists. And the smashed tube here should give you a clue that you can smash this tube, over here. But in all of these cases - as well as some other easy-to-miss passages later in the game, it can be a huge issue if the player thinks they’ve hit a dead end and goes off looking elsewhere.

This is when players can start getting lost - and frustrated - in Super Metroid. Anyway. The underwater world of Maridia is a bit of a maze, but it’s also very contained. After exploring all of zebes with the power bombs and grappling hook, you’ll likely stick to this one zone until you’ve finished off the third boss of the game: Draygon. Lke Zelda: A Link to the Past and Dark Souls, Super Metroid has a changing structure - with some bits that have you making quick forward progression, and other bits that have you exploring in a more open fashion.

And that’s what happens now. After getting the space jump. there’s a bunch of places where you can use it - like for getting the spring ball and plasma beam in Maridia. Or getting some goodies in Crateria. But the place you actually need to use it is down in Norfair, to get to Ridley’s lair.

The entrance to Ridley’s Lair is a bit weird, actually. So for one, it’s got three locks in a row. You need a power bomb to get in. Then the gravity suit to withstand the lava. And then the space jump to get up to Ridley. If you come all the way back here after getting each power up, you’re gonna leave disappointed. Twice. Also, this imposing head would be a very distinct landmark to put in your noggin if you just found it while exploring Norfair.

But because it’s behind an unremarkable yellow power-bomb door, you’re less likely to file this in your brain under “very important rooms”. But back to the adventure. So you explore Lower Norfair, find some more cheeky areas - oh, we can just walk through walls now, can we? okay - get the final power-up, the screw attack, and kill off Ridley. With the fourth boss of the game finished off, we should hopefully know it’s time to return to that ominous room in Crateria, and enter the final zone of the game.

This is almost identical to Metroid 1, only with four bosses instead of two. And the rest of the game is pretty familiar, too: we kill off Metroids with the ice beam and missiles. We fight Mother Brain in a jar. We - oh my. That’s a bit different. We have an escape sequence. Don’t forget to save the animals! And we escape an exploding planet Zebes in our spaceship. The end. Mission complete. Job done. Genre… defined.

So let’s look at that dependency graph again.

If we put in a red line for where the game lets us pass back over that point of no return, we can see a pretty sizeable shift. Suddenly, the game gets very wide, as there are loads of places where we can use items, and we can backtrack to every point in Zebes. And I think splitting Super Metroid into two distinct acts like this is a really good idea. We get almost a tutorial at the start. And then - once the game is satisfied that we get how things work - the reins are removed, and we’re asked to fend for ourselves.

But I do think the game struggles a little in this second half. Super Metroid’s Zebes is actually quite tricky to navigate, with spindly corridors and a somewhat confusing layout, making it slightly tedious to get from one end to the other. Plus, Norfair only has one entrance - this elevator - despite the fact that you’ll need to repeatedly return there. That makes getting around more difficult than it needs to be. Oh!

And until you find the wave beam, which lets you open those blue-button gates from the other side, the world has some annoying one-way paths that will need to be circumnavigated. In its favour, though, is that each elevator room branches off into a bunch of different zones: effectively a hub and spoke system, that makes for easy transport. And also, almost every single room in this game looks completely unique in some way, making it easier to remember their layout - especially compared to the very samey Zebes from Metroid 1.

Another way the game struggles is that the map screen is pretty unhelpful at times. You can’t see doorways between rooms, so two connecting areas might not actually join up. There are no icons for coloured doors. Secrets have the same icon whether you’ve found them or not. And, you can’t see the map for an area that you’re not currently stood in. All of this would thankfully be fixed up in the GBA games. Also, I think it’s a shame that Super Metroid is still completely linear in this part of the game.

I feel like this would be a great time to let players go off and kill the remaining three bosses in any order you like: but the game still makes you fight Phantoon before Draygon, and Draygon before Ridley. This is not the end of the world - despite what some people seem to think, I don’t think linearity is necessarily a bad thing. But maybe a missed opportunity. And it would help players who got lost if they could go off, explore another part of the map, and make progress there instead.

Then again, you can break this sequence. You can fight bosses in a different order, get items before you’re supposed to, and skip some upgrades entirely. How? Well, when you’re exploring the world in act two, you very well might come across these guys - a bunch of animals who will teach Samus how to do advanced manoeuvres. One lets you bounce off walls. The other lets you build up speed with the speed booster, and turn that kinetic energy into a massive jump.

And this is really interesting because they’re not actually upgrades, like the ice beam or morph ball. These are just advanced manoeuvres that samus can do - and could always do, you just didn’t know about them. So next time you play the game you can use these tricks to, say, get up here without the hi jump boots. Or to get over here without the grappling hook. Unfortunately, you can’t break the game apart too much unless you start using glitches and speedrunning techniques that aren’t taught to you, like the mockball and bomb jumping.

But it’s still something to make the game more interesting on later playthroughs. This is something Metroid does well, but many other Metroidvanias don’t really incorporate.

If the goal of a Metroidvania designer is to find a balance between letting the player explore on their own, but also not letting them get too lost and frustrated, then Super Metroid does a pretty stellar job. The game eases you in with a simple structure and one-way paths, before letting you run loose when you’re more familiar with how things work. It uses strong visual landmarks to help you build a mental map of zebes. and there are plenty of tiny techniques to subtly guide you forward.

And it also nails one of the most exciting sensations of a Metroidvania: by not always making the path forward obvious, you get the thrill of organically stumbling into an interesting new area. You can really see why this game has been so massively influential. But while it’s been copied by a million indie devs, critically acclaimed by reviewers, and held up as one of the best games ever made, it wasn’t a huge hit at the time.

And the Metroid franchise was essentially put on ice. We’d have to wait eight years for the series to finally return, on GameCube. Luckily for us, though, something quite similar came out in the intervening years. That's right! Next time on Boss Keys, we're putting the "vania" back in Metroidvania, heading to Dracula’s Castle, and exploring the world design of Castlevania: Symphony of the Night.