Awesome
It's a really cool game, great work! There's very many good stuff about the game but I'll concentrate on what I think needs improvement
1) The CPU cannot shoot anything above them. They will automatically shoot at the same angle but below them instead. This is a pretty big bug, which I really think needs doing something about it.
2) The CPU is generally really good and I have no idea how you managed to do it, BUT, it craps out sometimes, shoots its own in the head and stuff like that.
3) Why did you go for sticks? Its such a great oppurtunity to introduce some cool characters of your own of any design. I personally would have LOVED to be able to use my own characters for a concept as great as this, instead of chosing boring sticks.
4) I didn't like the music and it was too compressed, I do completely understand why but still... I'd have preferred 2 songs with twice as good compression than 4 as it was... But you included an option to turn it off so no minus for that!
Keep the good work up, make a sequel to this one!