I liked this a lot! Hard, but playable. Looks great! The crudely drawn scrolling intro made me laugh. The random levels are sometimes a bit unfair, when you get cornered immediately at the start by a large troup of mutant rats. I think each level should start of with not so many mutants nearby, and more mutants spawning later. Also, some power ups would be awesome! There's no way to quit the game? I had to kill it hard (on Linux).