Very interesting proposal, I really liked the dinamics generated trough the change of characters, althought I couldn't pass the first level. I got stuck at the end (couldn't figure out how to get the red guy to the top)
Also, I think generally is best to use the classic controls for the classic movements ("space" for jump, for example).
It shows you have put a lot of content in the game. This is awesome, considering the 72 hs deadline.