Pretty cool, and fun. Would be nice to see more enemy variety in place of just leveled up little guys. But it's a work in progress so I get it.
I've been working on a space shooter game, and as such I can tell you are putting a lot of care into this. Keep it up I'll be keeping tabs on this.
Also, I compose music and noticed a lack of music in your game. It's possible that down the road I could help you out with that if you would like. You can check out my stuff if you want an example of my music quality.