Cute little thing :) Enjoyed
Would be cool if it wasn't just about defending yourself from the rockets. Yeah, it's a highscore thing right now, but maybe you could get temporary super-abilities for slashing enough in a short time, or you'd get rewarded for getting aggressive somehow? Maybe you only fill one HP per level cleared and you can graze rockets to slowly get HP back??
Anyway, solid concept. Liked the models :)