Groovy music. I wish the AWSD keys worked like the arrow keys did. I like the MIB look of the limo you drive. Would be cool if there were more attacks -- was getting tilted by the UFO getting the best of me.
Is GameMaker easy to work with? I never tried it. Everyone always says Unity is the shit, but I messed around with it once and got super overwhelmed with all the stuff you could do.