Samus’ main goal in Maridia is to acquire the Space Jump, which you’ll need to reach the next section of the game. With Draygon down, that mission goes in the books as “accomplished.” However, I’ve only really talked about the critical path through this region. Maridia has much more to offer than simply a path to the boss.
More than any other region of the game — or in fact any other map region in the whole of the Metroid series — the design of Maridia communicates the notion that it’s a habitat — a wild, untamed region. The Space Pirates occupy it, and their facilities slice through it and separate the dry upper caverns from the flooded lower spaces, but unlike the rest of Zebes you come away from Maridia with the feeling that this place was never fully cultivated. A number of chambers in this area play host to unique and often non-hostile creatures, unlike the upper regions where everything is out to kill Samus.
Most memorably, there’s this guy. Or lady, maybe? It appears to be some sort of ankylosaur-type beast whose babies look remarkably like Buzzy Beetles. These ruminants occupy their own room, a space occupied by no other life. They’re perfectly happy to ignore Samus; if you run along next to them, they continue grazing peacefully. On the other hand, if you molest any of the babies, the parent goes berserk. (Don’t worry, though; the babies’ hard shells protect them from any and all weapons Samus has on hand.)
Bother the children and the larger of the creatures basically goes full-on Gamera — it retreats into its shell and begins spinning rapidly, trying to smash into Samus. If you hop on top of the shell, it’ll start flying up into the air, though it doesn’t rise high enough to smash Samus into the ceiling. It does, however, rise high enough to bring Samus within grappling distance of a single grapple block high above, atop which an Energy Tank sits. That’s right, Super Metroid actively encourages you to abuse baby wildlife so that you can become stronger. This is not really a good message to send, in my opinion.
Of course, if you wait to revisit here until after you’ve acquired the Space Jump, you can simply leap up and acquire the Energy Tank peacefully.
Then there’s this… guy? Unusually for Super Metroid, there doesn’t appear to be a biological component to this creature; in fact, it appears to be some sort of tunneling or boring mechanism. It simply sticks to a fixed pattern, roaming around the room it appears in by setting down one of its “feet” and pivoting around the most recently planted appendage. It won’t attack Samus, though it also won’t stop for her sake and will blithely injure her if she stands in its path.
Initially, the borer occupies a single small room which it circles infinitely, but you can use a Power Bomb to break down the wall to the right, exposing tender sandstone that Samus can’t break but which the borer makes short work of.
This is another spot in which the fixed position of the screen hides a passage forward — the screen won’t scroll right until you blast the wall on the right side. But there have been enough of these that you should be suspicious of the ill-fitting violet wall that hugs the right edge of the screen so conspicuously. On the other hand, you can easily destroy the borer with a few shots, so you might never think to investigate further. That would make you a pretty poor explorer, though. The fact that this path leads to a single dead-end room occupied by a non-aggressive robo-creature that appears nowhere else in the game should scream “Hey, there’s a secret here!”
And indeed, the secret here is no mere Missile expansion. Instead, you’ll find one of the final power-ups of the game hidden in this not-quite-dead-end: The Spring Ball. As in Metroid II, the Spring Ball allows Samus to leap while in Morph Ball form — and leap quite high at that. You can easily finish the game without the Spring Ball; this is a wholly optional power-up, one you won’t be penalized for missing. Between this and the Space Jump, it seems the theme of Maridia’s treasures revolves around reducing the fuss and bother of getting about.
For example, when you encounter these guys — another indigenous life form that only appear in a single room of the game — the Spring Ball makes getting past them far less annoying. These crustacean things spin toward you, and while you can roll over them safely to pass this can be difficult; the armor crest above their eyes actually registers as a slight irregularity in the creatures’ collision detection, and their spinning motion can scrape you right off and plant you on the ground. With the Spring Ball, though, you can get past them without brute-forcing bomb jumps.
And finally, perhaps the most enigmatic of all of Maridia’s wildlife: A pile of eggs. To my knowledge, these have no purpose or function within the game. They’re just… eggs. They sit in a pile and pulsate slightly, but I’ve never seen them hatch, and they don’t correlate obviously to any creature in the surrounding rooms. But they do fit the theme of Maridia as a region still teeming with native life, and fit neatly with the protective turtle-beast and its pups seen elsewhere in the area. For that matter, they echo the region’s boss itself, as Draygon also appears to be motivated by the desire to protect its young.
In the wettest place on Zebes, life finds a way. Too bad you’re going to blow up the planet.
Edit: Smarter people than myself have pointed out that these exist to show off the Plasma Beam’s piercing effect. On the way in, you can only shoot one egg at a time; on the way out you can vaporize them all in a single shot.
Speaking of Draygon’s spawn, they don’t only appear before and after the battle; they also descend into the sand in a pair of really annoying rooms. Between the quick-action suction of the sand and these stupid things burrowing into the ground and pelting you with globs of spittle, this room is a giant pain in the butt. Now, if you come back once you have the Space Jump, you can cruise right over the guys and find a secret hidden in the ceiling of a nearby room. And if you come back once you have the Plasma Beam, you can even fry these guys in a single shot, which is deeply, deeply gratifying.
The Plasma Beam, incidentally, allows you to destroy just about every creature that until now has been invulnerable. Maridia’s lavender Space Pirates in particular. Interestingly, these are the only Space Pirates that appear in this watery region, and their coloration seems remarkably similar to Samus’. Are they wearing Gravity Suits, too? Well, it doesn’t matter, because once Draygon is dead the locked door high up in Maridia’s sandy zone opens and allows you to grab the Plasma Beam. The satisfaction of being able to blast these guys, among others, more than makes up for the fact that the way the weapons is locked up (behind a door that opens when a boss dies, the same as the lock on the shortcut from Draygon’s chamber back to the Plasma Beam) is uncharacteristically inelegant for this game. Sure, doors seal behind you to force you to deal with a new enemy or master a new tool, but it’s strange to see a sealed door that simply opens and reveals some kind of prize for killing a boss.
Maridia still has quite a few chambers beyond what we’ve examined here, including some parallel one-way passages that make it impossible to acquire every item here in a clean run. You need to really explore Maridia and probe its depths in order to clear it out. It’s by far the most open portion of the entire game, trusting in you to have mastered the basics and have learned to explore on your own. Many of Maridia’s treasures are optional, so you can survive without them… but the more you explore, the easier a time you’l have with the remainder of the game.
Anyway, that’s Maridia. From the shattered glass tube connecting Maridia to Brinstar, it’s a quick jog to your next destination. Of course, you don’t have to go that way, and in fact there’s a third exit from Maridia that takes you to an early room in Brinstar. It’s a one-way door, incidentally. (One of the game’s crueler pranks.) At this point you basically have a fully equipped Samus capable of going pretty much everywhere in the game. All those secrets you couldn’t quite reach before, especially those you had to pass up because you couldn’t leap or dash through water, are within your reach now. With the Space Jump, you can go everywhere, including…
Ridley’s lair, deep inside Norfair.
In a clever twist, there’s a little dead-end passage that leads to this portal — you can see it above. You can roll there fairly early on and scope out your next destination. But you couldn’t actually reach this entrance until now, because not only does the translucent magma require the Gravity Suit for safe navigation…
…the enormous magma chamber beneath the entrance necessitates the Space Jump. It’s far too high a space to jump, and those stupid alien head dudes would make bomb jumping impossible. On top of that, the prospect of cheating with wall jumps is out of the question thanks to the spikes the line the upper wall and the underside of the lip beneath Ridley’s vanity portrait. But kitted out with just about every bit of gear to be found, you’re good to go.