Been done before
When I played this, the first thing that hit my mind was the wacko controls. First of all, it would be much better if you were to give the control to the mouse. Have the ship follow the cursor all the time. That's just what I think.
Also, the whole point of "Star Collecter" is to Collect stars, right? How come it's not necessary? This is just like any other game where hordes come at you, except this one you can go out and get extra points. Even that's been done. If the stars were necessary to get, say, the upgraded guns, then you'd have something more original.
Also, I think the upgrades should be interchangable, because In my opinion, upgrade 3 was a hell of a lot better than 4.
But hey, overall, I did enjoy playing. Don't think it isn't fun. It's just not extraordinary.
Keep up the good work. I have a feeling you could do great things.