Aw snap, someone get the holy water. Open Source Zombies!

Grab whatever you can - pitchfork, chainsaw, hatchet, or a shotgun for those of you who can't be bothered to "finesse" a zombie into submission. Your goal in this addictive little game is to save as many of the humans as you can from a horrible fate no doubt involving their brains being eaten.

It's set up kind of like a chessboard, with humans and zombies randomly placed. Set your difficulty and gore level, and go to it. Use the right and left arrows to turn your character around, then walk them with up and down (preferably over a weapon). Next to a zombie? Turn to face it, move towards it, and you automatically attack - you may miss, of course, so make it count. Grab a shotgun if you can, they've got phenomenal stopping power (read: one blast and you've got yourself a heaping pile of zombie slaw).

The graphics aren't great, but who cares? Zombies is ridiculously fun, only 7MB to download, doesn't require an install, and runs on Windows and Mac. Everybody wins! Linux users can play too, you've just got to compile the included RealBasic source code yourself.