no no no this is wrong wrong wrong
The only well designed environments were SkyTown and Phaaze, the latter of which is tainted by the awful gameplay twitch forced upon the player.
The music is okay, but that's it. Not good like MP or great like MP2.
The enemies mostly look ridiculous. I'm not sure why the Space Pirates and Metroids needed to have their appearance changed to something ultimately more silly looking than the previous titles.
The three other hunters were welcome additions - indeed, one of the things I was looking forward to was interaction with other characters (as opposed to just blowing them up and reading their logs), and the three of them had pretty interesting designs (especially Rundas, who looked very similar to Noxus from MPH, so I had assumed they would tie into that. Of course they didn't.). And they were all implied to have a previous relationship with Samus, which had the potential to give not just them but Samus herself a bit of actual development.
But boy, was I disappointed when not even 20% into the game, they suddenly become bad guys for stupid, stupid reasons. The least they could have done was either have them corrupted near the end of the game, or had them not just die and be 'absorbed' by Dark Samus whenever you beat them. That was a lazy, lazy move of them.
No multiplayer - ridiculous. As shallow as it was, the multiplayer in MP2 was one of it's best assets.
And finally, the bosses were just so so so bad. Especially compared to MP2s bosses. Mogenar was slow and unimaginative, Helios was pathetically simple, and Omega Ridley is almost a copy of Meta Ridley from MP.
Don't get me wrong, it's still top of the line when it comes to Wii titles in general. But for it's series - it was a disappointing low.