Not bad. I loved the visual style of the game and the mechanics were really smooth. It could use some sounds for sure, and the spawns stop coming when you hit 14.600 in score. Also, some off screen colliders would be great. I noticed that I can run off either side of the screen and basically just drop off the world completely.
I really liked the physics of being moved by the guns as you shot. Overall, really fun, but I found it really easy, and I wanted to keep playing after 14600.