It has a few bugs, like you can get stuck with the big guy, or you can fall through platforms. Also, I think you should either create an easy restart option (like pressing R will restart the level), or design levels in a way that you can't get stuck, e.g. on the 3rd level if you go down to the left with the small character, you can't get back up.
Cool game though, I liked the visuals, and it has much potential.