i've always liked how the melee metroid stages have bits of recognizable metroid imagery scattered about them but in totally nonsensical location and function
i really don't know what they were going for with those stages lol
Don't get me wrong, I've always liked Brinstar to play on and Brinstar Depths, while not exactly fun, did have the "holy shit Kraid" factor to it. But I did like in Brawl that they made some actually identifiable Metroid locations. Like, as much flack that Norfair gets for redoing the rising lava gimmick, it is identifiably Norfair, at least its background is.
Unfortunate that Pyrosphere is probably the only new Metroid stage this go around, because there's too many good Metroid environments to have the only new stage be hamstrung by Other M's incredibly boring and sterile art. And it's not even an interesting looking location by Other M's standards, even. A location that shifted between organic and man-made would have been much more interesting, and that was the most original idea Other M had, art-wise.
Pity it's also probably ruined by a super intrusive boss character. I didn't used to think so, but Smash 3DS has shown me that Smash Bros. is in desperate need of an actual stage hazard switch.