Its pretty good! Its a little tough to aim in the modes where you can't activate it on button press, but not to the point where its game breaking. Its decently fluid as well.
Yea... the controls are a tad slippery(whats it shooting out, gas?) and the levels are quite ridiclous. I would get rid of actually picking up the money( make an upgrade to pick it up) someway to increase your health bar(defenses N such) and cut down on the amount of stuff on the screen.
Still a pretty great game, but far from perfect.