Nice.
Attention all game makers: THIS is how to make one. Simple concept, great controls, looks nice, flows well, quick, interesting, and just plain enjoyable. If I was going to suggest any improvements, I'd say the following: More power-ups that preferably last longer, add a never-ending mode to see how far you get (not easy, but possible), perhaps some different music options (though the track used was perfect) and make the target reticule a bit more obvious. Quite a few times with the intense action, I had no idea where it was...
But even those points are tiny. What you have created is something rare: A great game. For that you deserve a lot of praise. I look forward to a sequel!