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.
Such a great game. Sure it's been around for a while (and free for some time too), but the Desura client makes this so easy to install and run. What's not to like? It's free and it's awesome. Download it now!