Eh, I dunno. I don't really care what's done with my character in the game, but just in case:
Appearance:
Gameplay: Boo Mario style.
I think there should be walls that I can't go through unless I'm invisible, like in SMG. And I could float, too. I can avoid all these enemies. Just an idea, but would it be okay if I had the power to use Yoshi's Tongue? That would probably be my only attack, beside the spin jump.