Until the Metroid Prime Trilogy came out, Metroid Prime 3 was probably my favourite Metroid game for one simple reason: the controls. Oh my god, the controls.
This was a complete and full delivery on the promise of the Wii control system being absolutely perfect for FPSes. None of this Red Steel "drag and pull" the screen nonsense – Corruption pretty much mounted and stuffed that old bullshit. No, here was an absolutely fluid and marvelous point and shoot control system married to a freaking Metroid game, and an excellent one at that.
This is the culmination of the Prime series, and it's a good one. Basically, the game does away with a lot of the things that defined the Prime series up to this point. You never feel quite alone – there's other troopers fighting by your side, and the Aurora Units (the organic supercomputers that are at risk of being infected with Phazon by the Space Pirates) speak to you as you make your way through the game's worlds. It's a risk that absolutely could have backfired if not handled well, but the game still has enough of the Metroid charm to pull it through. Not to mention that the game just feels like the end of a trilogy – epic and operatic in all the right places.
Interestingly, another element of past Prime games has been eliminated as well, and that's the concept of a connected world. Adding to the grand scope of the game, Corruption allows you to fly to three or four different, self-contained planets, which really works – it's just an interesting way to do the same things that you could do with a connected world in a different way. It also puts a focus on Samus' ship, which is more important (and also cooler-looking) than in any other Metroid game.
Unlike Echoes, Corruption is a game with perfectly balanced difficulty. It's still supremely challenging, but the progression feels natural and organic. There's no blastedly hard fetch quests (except maybe one where you have to grab power cells to charge up a tower, but even that's not too bad), no overly hard enemies – it all just feels right. I think that perhaps some of the challenge disappeared with those glorious controls, as I certainly found the original Prime to be quite a bit easier than when I had played it on the Gamecube for the first time.
Where Corruption hits its highest notes is in its absolutely astounding art design. Save for the Mario Galaxy games, this is the best looking game on the Wii. The various worlds – the biodiverse planet of Bryyo and the skytrains of Elysia in particular – are all rendered with exacting detail, and the Space Pirates' hideout is a masterwork of gnarled technology run amok. Even moreso than both of the previous games, Corruption is a game with some amazing sights.
The main new gameplay function (and the place where the game takes its subtitle from) is the ability to inject Phazon into Samus' suit and enter into "Hyper Mode," allowing you to crush enemies with single blasts. Yet, with this added power comes the ability to overload your suit, leading to Phazon Corruption, one of the most eerily horrifying "game over" screens I've ever seen. What this ability does is it organically deals with two problems from the last two games – one, it allows for the game to have a "dark world" that isn't so segregated and purple as in Echoes; and two, it allows the game to start Samus off with most of her powers in tact, and to simply acquire new ones. Explaining away Samus losing all of her abilities made a certain amount of sense in Prime 1; less so in Prime 2.
I guess after writing all of this, what I've basically done is I've convinced myself again that Corruption is my favourite of the Prime series. The first Prime will always have a special place in my heart as the first game to get it right and to take the Metroid series to glorious new heights, but Corruption refines all of that into one of the most supremely playable and intriguing games to come out in years. Hell, this game even manages to make the Hunters seem awesome – any game that can do that deserves only the highest marks in my books.