GREAT!
I just beat it, and I have to say I'm really impressed. I see either immense effort, or a crapload of experience in Flash Actionscript. I'd have to say it's one of the best little games I've ever played.
PS: Make the canvas size 480x272 and make it so that you fire by clicking on the screen and you'll be able to put it on a Sony PSP!
Please read this and add the changes, cause I'd really love to have it on my PSP.