Just wanted to throw my two cents in on the subject. But before I do… Metroid as 2-player? Like, the original Metroid? Or am I just reading it wrong?
Anyway, I don’t mind 2-player alternating games, though I think Nintendo had improved on it for a while there. Truth is, I wish that Nintendo did MORE of them now. Super Mario 64 and Super Mario Sunshine come to mind, specifically. Those are two games that I think could benefit from that sort of teamwork, like in Super Mario 3 and Super Mario World, where you worked together to clear away the stages, and you’d pass it off, either if you die, quit a stage, or clear it.
I admit, SMB1’s style didn’t work too well until the Super Mario All-Stars version, where it was more turn based depending on if you died or cleared a level. You could practically never get a shot to play once for 32 levels if your friend is good enough.
Unfortunately, if there’s two of you, the latest Mario offerings can be just plain BORING with only the one-player feature. I think if implemented like in SMB3 and SMW, the games, Sunshine in particular, would’ve been a lot more enjoyable for us in the long run.