About five months ago I played Zombeer and it was nice to not have to think so much. It was a breeze. I'm looking for any good run & gun fps games to play that don't require too much time, focus or thought. I want something to run through and mow down hundreds of enemies, something that is pickup & play. Potentially something like Doom (which I have already) but with even less of a story. Got any good ones for me?