Valve has just flagged Left 4 Dead as alive (as it can be) and playable on Steam. It has been available for pre-load and pre-purchase for a while now but it is now officially playable. For those of you living under a rock, Left 4 Dead is a co-op shooter built around the situation of 4 human beings attempting to survive a zombie apocalypse.

Good news for you zombie killers out there. Straight from the horse's mouth we have word that Left 4 Dead is now live and available for purchase AND play via Steam! Shoot 'em in the head!

JelalTrueshot via gamingshogun.com »