Okay, this was really fun and really adorable! The game involves a lot of trial and error, but it's the good kind of trial and error, where the movement is so exhilarating you don't mind trying again and again and again.
My suggestions would be a level select screen, so we don't have to start over whenever we want to try a different character, and a quick retry button, so we don't have to wait for our character to reach the kill plane before we can restart.