Not too shabby.
This is a beta, after all, and should not be treated like a finished game. This could be a ton of fun when it's done (hey, that rhymes...), except you should try to fix that 'invisible box' thing, as it's really annoying. Also, if possible, add some more enemies in the final one. Other than that, good job (it's a lot better than what I could do; I know shit when it comes to actionascripting).