Ohhh, this was neat. As soon as I realized my screen wasn't screwing up, I really liked the window effect that was going on. Along with the Kirby-esque health balancing, I would love to see this kind of thing expanded with more opportunities for mechanics.
I think movement is a little too floaty in that I ended up hitting some spikes I shouldn't have, but it wasn't really a problem for me what with the length of the game, the health-sharing, and the surprisingly competent AI platforming (minus getting over a couple of ledges). Also helps that it's a pretty looking game.