Really neat concept that could definitely be expanded into more. I really liked the improvement mechanic where you defeated the asteroids and then when you defeated a certain amount you could use those point to upgrade yourself. It was also a nice touch when your shot color changed. However, I did not like the increase of difficult right after each improvement. I definitely feel that this could be a gradual change after every few upgrades. I also wished there were sound effects for shooting and destroying asteroids. Overall though, nice work!