I really, really enjoy playing this game. Simple and fun, solid controls, etcetera etcetera. I like how quickly it becomes chaotic. Suggestions: 8-bit music, and a new shield mechanism. 8-bit music would obviously fit this better. Sorsorsor has a good idea for a shield, a couple of the levels are just too difficult to have the limit on shields that you've alotted. I have completely maxed out the ship, and can't seem to beat the last few levels.
Anyway, good game! I hope to see those small improvements in the near future.