Ok, interesting concept, You need to work on a lot of problems though. first of all, i hated the control scheme. mouse to move and to shoot was really hard. (Aiming was almost impossible.) Your sound was okay, but when it got to programming, it glitched out badly on the 3rd level because of all the moving sprites.
One other thing that bothered me was that there was an ad I had to sit through between each level. I don't know if you have control of that or not, but it's kind of annoying. Good luck on your game making!