Left 4 Dead has become a staple at our gaming sessions here at GamerFront, and the new Survival Pack has kept us really busy. If you haven’t checked this game out yet, then you’re in luck. Today you can play the game for free (until 12:01AM GMT) through Steam. I’d suggest getting your download started before you head off to work (or school) since there are around 5GB worth of files. Even better, if you decide to buy the game this weekend, it can be had for $23.99 (that’s 40% baby!). What are you waiting for? Those zombies aren’t going to kill themselves.