Your game is simple but solid. The controls are good, the art is amazing, sounds are perfect, and it is really really juicy. I really enjoyed it. My only grievance is that some enemy patterns seems nearly unavoidable if you happen to be on the wrong part of the screen when they spawn (I'm thinking about the tight three eagles formation). A simple way to fix that would be to move the player more to the left of the screen. Right now that's half the screen that's not used, so doing so would allow the action to take place on more screen space, but most of all it would give the player more time to react. Sure the game would be easier at the beginning, but it would be fairer and the difficulty would ramp up with the speed anyway. I don't think increasing the average survival time of your players is a bad thing overall.