Wah, I almost missed your edit: very cool video.

Demo is very cool as well. But I thought the one who can crawl is the boy, not the girl? cause the girl can switch gravity, but the other person can crawl...?
Speaking of switching gravity - the double jump works pretty much exactly how I imagined it: that's cool!
The rotation animation for the double jump could be a little quicker (I'm thinking of mario 64's triple jump).
The multiple-layer thing works really well.