Fun design. I liked the paint theme and the funny bosses.
I agree with others it was kinda annoying to aim. I would've been happy if I could stop on an angle to shoot diagonally, but I had to keep moving or else I would go back to a 90º angle. I ended up just lining myself up and shooting in a straight line when enemies went past me. It made the smaller enemies more annoying to kill than hard to kill. It just took time, not skill. And I don't think that's what you're going for.
Smooth gameplay otherwise though, and I already said. I like the paintball theme a lot.
D