You have been locked in a prison where illegal genetic experiments have been going on. The scientist figure out how to genetically make anyone go into a rage. They call it the Abuse virus. It has gotten loose and spread through out the entire prison. You have to fight your way through all the mutated and enraged enemies and make sure this doesn't leave the prison.
Awesome platformer with great atmosphere. To my knowledge, the first one to allow you to aim with the mouse while moving with the keyboard. Only thing I don't like in it are the jumping controls.