Going from zero Metroid games in eight years to three in two years was a welcome change. But why do both of spacey-chic heroine Samus Aran's first-person adventures have to be so damn similar? Per usual, you start with the most basic of sci-fi equipment; a meager blaster and roly-poly, morph ball for locomotion. Eventually, these make way for multi-targeting missiles and a chasm-spanning hover jump. As you explore the rocky, swampy and airless terrain ot the planet Aether, new paths will open up. Naturally, some areas are just out of reach, so continual exploration is needed. Heard it before. The twist with Echoes is its balancing act of dark against light.
While responding to an SOS, Samus sees a shadowy, ring wraith version of herself finishing off some space marines. Hot on this Dark Samus' trail, you pass through a milky-black portal that launches you into a mangled, beat down version of the planet you were scoping out. Its searing skies and toxic lakes eat away at your health, and some of the strangest, poison-spewing creations space has ever seen are sweeping in and out of the darkness. Tiny, splintered beacons of light offer brief pockets of safe air, but there's always something lurking nearby. Running around this hostile landscape, all alone, seems about as smart as playing in an airlock. Yet you proceed, driven by the mystery of just who your evil twin is.
It seems there's a civil war brewing between the planet's two anti-races, each of which rules one version of the planet. The angelic Luminoth live in the light phase and are on your side; the parasitic Ing, who hang out in the emotionally devastating dark version of the planet, always have their inky tentacles somewhere near your armored throat. The aliens' duality mirrors many of the puzzles you'll face in the game. The two phases of the planet share caves, mountains and other topography, but have them in slightly different places. A blocked path in one world may be clear in another, so zipping back and forth through the scattered portals is the only way to rub out the Ing for good.
Beam weapons and armor upgrades are expected in any Metroid, and there are dark- and light-themed cannons to grab, but their functionality is limited. Dark is weak against light (whoo hoo). Samus' info-collecting visors, now in infrared and sonar flavors, show the world in different ways, but feel much like the previous Prime's viewable options.
Other than a few superficial tweaks and some vanilla, offline multiplayer, the rest is exactly like the first Prime. The same organic, layered environments and completely convincing scenery envelop your senses, further aided by the visor-cracking sounds effects and haunting music. It's very close to a total rehash, but the poisonous dark world mechanics add even more atmosphere to a series that's already one of the most engrossing, rewarding experiences out there.