Damn, a lot of whiners about this game.
Don't listen to the haters, this game is a pure shooter. Don't expect anything else. While it's not A+++ material I'd definitely give it a B or B-. The game is all about learning how to use the layout of the level to your advantage to dodge enemy attacks while countering with your own. A lot of the music is great, ranging from techno beats to ambient electronic.
And while the controls aren't as easy as some people like, they are rewarding if you can learn and master them. If this game were controlled fully 3D like say, Zelda or Mario, this game would be a cakewalk.
Again, if you had any interest in this game 10 dollars is a steal. This is for the hardcore elite only.