Nice, original idea, but...
...it doesn't take any strategy. All I did was rotate in one direction and shooting continuously and I got up to 6000 points before getting bored.
Limiting player shots would help -- and as others have said, smarter opponents.
Well actually, There was no music, no instructions, and the graphics weren't so good. 4/10. You should have spend time for the instructions.
It's pretty good
Could use some background music, and maybe more difficult "enemies." I think if you update this in the future it'd be a lot better.