You can get a duck hat, then send out a frog with a bomb in his mouth. 10/10

One of the best co-op games on steam. Get some friends, and kill some zombies!

I like Fallout 3 better, but this is still a really good game. If Fallout 3 doesn't work on your computer, get this instead.

By far, my favorite game of all time. If you can get this game to work, you'll be in for a ride.

If your looking for a game that has a competitive feel, but also a game that doesn't take it's self too seriously, this is the game for you.

This is what I think of when someone says Steam, valve, or FPS in general. Humor, skillful, hats, great community, great design, this game has it all

This game shows you how to make a crazy, hilarious, skillful, and fun game. Grab some friends, and have one of the best gaming experiences out there.