Prime 3 retains the foundation of the Prime series and adds some interesting ideas of its own on top. And yet, the game never quite appealed to me in the same way the previous two did. There's a plethora of strange creatures to fight, unique areas to visit (SkyTown's aesthetic is like nothing else in the series, and a fan favorite for a reason), lore to scan, and a narrative that not only has greater stakes than the previous games, but feels like what the series had been naturally building towards. Whereas Prime 2 fell into the hole of reusing a lot of Prime 1's ideas, Prime 3 feels like it stands on its own much more. The theme of “corruption” is felt throughout the entire game, and while hypermode is a gimmick that doesn't add too much interesting to Prime's core gameplay, it at least fits thematically and allows for a cool climax.
In Prime 3's ambition, however, it loses a lot of what made the first two games special. To me, Prime 1 and 2 are games about asking why. Why are things here as they are? Why are all these creatures so aggressive? What happened to this place? Prime 3 is a game where you shoot things because the space government told you to. In fact, you're practically a part of the space government's space military in Prime 3. Prime 3 is no more linear than its predecessors, yet it feels so much more so because you're following orders the entire time. Leaves a bad taste in the mouth. And besides, in a sci-fi setting filled with all sorts of crazy alien species, Prime 3 has you spend the most time looking at the boring space military comprised entirely of boring ol' humans. Another thing to consider is that where Prime 1 and 2 had immersive, interconnected worlds, Prime 3 practically has a level select. Prime 3 strives to expand the series' universe, but in doing so, it spreads itself too thin. Each of the individual worlds' stories are interesting, but the game simply doesn't have time to explore each in quite as much depth as Tallon IV or Aether.
There are a few glimmers of brilliance in Prime 3. I was caught completely off guard my first time stepping on board the GFS Valhalla, and had to take a moment just to take it all in. The atmosphere was unlike anything I'd experienced before, inviting a sense of wonder greater than what Prime 1 or 2 could ever elicit. A much smaller, yet memorable moment came in Elysia at the secret xenoresearch lab. As soon as you scan that pirate outside, you realize what killed him and it dawns on you what lies beyond the door. And then there's that perfect “...oh” moment as soon as you take out the Energy Cell and realize you've just released all the Metroids from confinement. It's good stuff. Not to mention the game's climax, and the perfectly unsettling atmosphere it gives off all the way through (you thought the Impact Crater felt disturbingly alien? Wait until you see where what made it came from!). Prime 3 strives to be an epic conclusion to the trilogy, and there are moments where its scope amazes. But that ambitious scope also leads the game to lose sight of some of what made Metroid Prime Metroid Prime. Teaming up with the military to fight aliens feels like something more out of Halo than Metroid... distinctly not my taste.