Very Impressive

I really liked this game. The graphics, interactivity, and sound were top notch.

My one feedback is that the power-ups were too hard to get. It would be nice if you could shoot them, or they stayed near the center of the screen.

give credit to the person who built this engine

I recall seeing this physics engine .fla for download on a site a while back, and I have seen several other games based off of it as well.

The least you can do is give credit to the person who programmed this physics engine.