So the developers did a version of the game where instead of shooting with a light gun, you type words to kill zombies.  It sounds silly, but the game is a lot more fun than you would think, plus it is great typing practice.  It's 50% off on Gamestop today:

http://www.gamestop.com/pc/games/typing-of-the-dead-overkill/112496

 

I highly recommend it (unless you can't touch type and don't want to learn).