Congrats! your game (for me) it's one of the most fun I have until now. I wanted to rate it after getting all the enemies, but I already have played 1 hour. I will come back and try again.
It's a very balanced game overall, good graphics, good music, fit the theme and it's very fun. Maybe the originality is not that high but I don't see it as a problem it's very well done. The enemy patterns got better with time and it's easy to retry. Good job!