I agree with the others about the polish, and I enjoyed the music and sound effects. But I felt it was hard to aim at flying enemies, and it was easy to cheese all enemies by just spam going the edge of the screen. I think a prediction line would have been nice for the aim, and if enemies followed you through the map edge it would make the game more challenging.
I have a low attention span and had a hard time playing longer than a minute or two. I enjoyed playing and keep at it you did a great job!