Well, I liked what you were aiming for, with vibrant colors and the concept of keep shooting to receive less damage. But, I couldn't understand where I was supposed to shoot, as nothing seems to change when I do. I thought, given the "be always shooting, but be careful where to shoot" concept, that there would be places to try to hit. I think that this concept definitely has potential. Also, the music is really nice and fitting!
Oh, and I would suggest to use only keyboard input, as you can't aim with the mouse anyway.