I must say, very nice game, simple and dynamic, especially considering the time invested in making it.
I would consider adding the controls section in the description, they are intuitive but I think it would be nice to know them before checking out the game.
I also had this bug with high health, happened when I was in a collision with the last pink enemy in a wave. Also had real trouble hitting him with a projectile, no matter where I aimed it looked like the projectile was going away from him. Might be just my poor aiming, not sure, it was just that 1 time.
Good luck with the game.