Really cool idea dude! Best I could do is wave 8. I like how the player gets their health back after every wave, it's very refreshing. I think the one thing this game could use is more enemy types, maybe in later levels when you have a bunch of different enemies you also land on bigger planets that have some varying terrain. One thing I noticed, you can still shoot the worm things for a little bit after they burrow underground. Otherwise the game functioned perfectly. Good job dude!