If your PC is slower than 2GHz you'd better to go to options screen and turn Blood Says and Interactive Enviroment off and turn Simple Shells on. Also, set music volume to maximum.
Cool 2D shooter with great physics. Shot your enemies, blow 'em with a grenade, make a fast moving cart smash them, or just drop a box on their heads. Face 11 types of enemies and break through 22 levels of fun.