This is made in Scratch? :0
Really like the game, and getting into a flow is really fun. Like other people said, it needs more juice (fire sounds, enemy particles, etc).
The one large problem I have with the game is that the key to reset is the same key as to fire your weapon, which leads me to never see my final ranking because I'm always hammering down the fire button during the game. Reset should have been LEFT + RIGHT + SPACE in my opinion.