Awesome game
If only all overhead shooters could be controlled like this. That's what you do in all of them anyway, backpedalling and shooting. Genius man, genius.
My only few suggestion would be:
-An option to turn down quality, for crappy 6 year comps like mine :P
-An option to turn cash drops off, when you bought everything
-Make the songs loop more than three times, for those long scorehog runs :D
... and maybe an even more ridiculous gun for like 10 000 000 ?