Eh....
The graphics were ok, and the gunshot and explosion sound effects were decent. You probably could have put in more and better weapon upgrades (I didnt notice any visual change after the 2nd upgrade to the 3-shot spread). But I was able to tolerate these...but not the following two fatal flaws.
The first major flaw is the music. The nice, happy, soothing relaxation music just completely ruins the mood, and DOES NOT belong in an aerial action shooter!
The second, and more serious, flaw is the controls. Some people (like me) absolutely hate mouse-based controls in aerial shooters. You really should have put in the option to switch to a key-based control system (like the traditional Up-Down-Left-Right keys). It was also kind of frustrating that I had absolutely no control over my speed, since there were situations where I would have been able to survive if I had just had a little variation in my speed.