This is one the best-feeling and most fun shoot-to-move games I've played! I'd say you have your core character controller down pat. I also like the decision to leave it up to the player when the next wave begins -- I think that's important when they don't have control, so good thinking there.
Where'd I'd love to see a little more polish is on the level art. It was sometimes disorienting to be flying way up high, and if there was a background layer with some kind of pattern or image on it (which nevertheless doesn't distract from fore-ground action or conceal enemies, items, or the player) that would make "grounding" myself easier.
Honestly, I'd just love to see more levels. I think you have a really strong game here! Keep up the good work!