Great Game!
I'm feeling a little under the weather, so while I'd normally write this review all flamboyantly, I'm just going to tell you what I liked, and suggestions for improving it.
What I liked: First of all, the music is bloody brilliant. Absolutely LOVED it. The only thing I would change to give the Sound category a 10 is perhaps some sound effects. Not for the laser, though, because after a while that would just become annoying. The style is pretty interesting, and the gameplay was fun, although lacking variety. Damn, do those things keep coming at you. My wrist hurts from the effort :) . Anyway, your game makes it so you can't stop paying attention for a second, and that's a good thing. Oh, I also liked how you get to choose between getting points added to your score, or cash. Reminded me of Dirge of Cerberus.
Suggestions: First and foremost, when a level is over, make us press enter or something before you go the shop. I bought too many things I DIDN'T want to buy, because there's no warning when the level is over. All of a sudden, the baddies are gone, and I'm rampantly clicking the "+10" laser size button, or converting more score to cash than I'd like to do. Definitely add that in. Another thing I'd do is depower the Wave attack. All you really have to do is save 1200 cash and buy it, and then you just click the mouse every now and then to eliminate all the enemies. It makes the game WAY too easy at that point. Oh, it'd also be nice if we could upgrade the shield without having to lose it first. Just a thought. Finally, the graphics need a little tweaking, make em a bit more polished. Escpecially the menu, it just looks rushed and...unspecial.
Ultimately, it was a very fun game, and I played it for a good 5 or 10 minutes, which is long considering my attention span. Just clean it up a bit, and I actually think you have some FP material here.