I liked it a lot, very nice game. It could be improved, though.
I agree with Antro and doomcat, you could have more enemies at once, and have more powerups.
Oh, and also, please add Kongregate API, so we could have some badges.
The game is fun, but its too easy. Also, lacks playability, since you can only go forward...space bar sucks for controls. Should be arrows, and you should be able to go back, at least.
Also, the guy is too slow, and the machine gun sucks.
Its a nice clone, but the physics seem a bit off. I can touch the ball with the end of the platform, and sometimes it goes straight, and sometimes it goes in an angle.