Good start, but could be much more.
I like this one- the controls couldn't be easier, there isn't any lag like I would normally expect with so many entities on screen, and who doesn't like blowing things up?- but as it is, the replay value is pretty minimal, since you are basically just bouncing around the screen looking for copters to hit. I would suggest adding a little variety- more varieties of copters to blow up, some obstacles that can blow your own copter up, power-ups (more fuel, larger copter, things like that), and maybe some terrain other than empty sky. It's a very good start though.