With the surprise release of a remaster for the switch, there's been a resurgence of interest in Retro Studio’s Metroid Prime, the first 3D entry in the Metroid series. Prime is the first and best received game in a trilogy of first person adventures. Its immediate sequel, Metroid Prime 2: Echoes, is conversely regarded as a kind of black sheep. Echoes is unfairly maligned for a handful of design choices that distinguish it from the original Prime. These decisions make the game more hostile—and more interesting.

The core gameplay loop of Metroid games is straightforward: while you try to progress through a science-fiction world, you periodically come up against obstacles that are presently insurmountable. These are sometimes arbitrary (e.g. a locked and coloured door), and other times a little more diegetically interesting (e.g. a magnetic rail), but the basic idea is always the same: you must go out and find an appropriate upgrade to Samus' arsenal, which functions as a "key" to these "locks" impeding your progress. Consider a recurring example: hazardous environments. In most Metroid games, there is an area your character cannot traverse without suffering continuous damage. This acts as a form of environmental gating. You cannot get through this area without dying, and so must leave in search of an upgrade which will allow you to travel through without consequence.

In its adaptation of this convention, Echoes distinguishes itself from other Metroid games. Prime 2 is set on Aether, an alien world that has been dimensionally split through the impact of a radioactive comet. Large chunks of the planet now exist in a parallel universe, and the sentient race who inhabit Aether (the ‘Luminoth’) have been locked in constant war with this alternate universe's monstrous inhabitants, who invade the primary planet's surface through interdimensional portals. By the time protagonist Samus Aran arrives on Aether, this conflict has been raging for fifty years, and the Luminoth have been driven to near extinction. In order to save the Luminoth—and herself—Samus must venture through the enemy’s interdimensional gateways and into Dark Aether.

Players familiar with Metroid’s conventions will understand the function of Dark Aether immediately. Its atmosphere is toxic, which makes any attempt at progression without protection apparently suicidal. Unlike most such environments, though, the player must venture onwards anyway. As the player proceeds through the perilous otherworld they discover remnants of the Luminoth's own attempts to explore their enemies territory: ‘light crystals’ are scattered about the land, that once activated create small pockets of protection from the poisonous atmosphere. These crystals are small and spread out: the player is forced to dash from one bubble of safety to the next, their health ticking down whenever they are unshielded. This is not the only threat in Dark Aether. The tenebrous creatures that inhabit this terrible world try to stop Samus at every turn, forcing the player into combat with fluid-like enemies who can navigate the environment with overwhelming spatial freedom. Even if you were unconstrained by the boundaries of protective light, these creatures would still outclass you.The whole experience is tense and uncomfortable, and feels distinctly disempowering—an unusual emotion, for the franchise.

This is, of course, a temporary state of affairs. At the climax of the first major segment in Dark Aether the player defeats a boss monster and finds a suit upgrade that allows them to freely manoeuvre through the shadow realm. At least, that's what you are meant to assume. The Dark Suit (as it is called) is not actually a complete barrier. It provides some protection, but that just means the toxic atmosphere eats at you just a little bit slower. To make matters worse, from this point on light crystals are spread out much thinner, and soon the player is compelled to fight shockingly difficult mini-bosses in arenas that don't have any safe zones at all—battles where time is as much an enemy as the boss itself.

Dark Aether is, above all else, oppressive. Everything about it is uncomfortable. It looks poisonous and sounds even worse: strange noises drone against the music while Samus's suit sizzles in contact with the atmosphere. Its inhabitants are corrupted variations on wildlife from the planet proper, or else, utterly unique shape-shifting creatures of darkness. Its air and water eat at you constantly and unavoidably. Brief solace from the corrosive environment is found only around forgotten relics: ruins from a war of extinction. Ruins that did not, and could not, protect their creators—a fact you're keenly reminded of each time you come across a Luminoth corpse, or face off against their war machines, long since corrupted by the world they were built to destroy.

Metroid games have always used the harsh environments of their alien worlds as a way to gate player progress, but Metroid Prime 2 takes this bare mechanic and turns it into a narrative device, using it as a kind of characterization. Dark Aether isn't just another lava filled cavern: it is not just inhospitable, but rather actively, volitionally hostile. One feels as if the world itself has agency—as if it hates you as much as it seems to hate everything else under the light. Dark Aether was born of a cataclysm, and has spent every waking moment since trying to consume its mother-world. It will eat you too, if you let it.