I think the last ship you unlock should be better, all those kills and I'd rather fly the previous one. Doesn't give me a lot of impetus to continue playing.
I'd really like it if this game had a pause button in the single-player sectors. I like to play at work and would love to be able to switch back and forth between work and play without dying.
I like the idea. I don't like that everything kills you. You should be able to go off the bottom of the screen and there should be a life bar of some kind. 3/5