We’ve been surviving Left 4 Dead’s desolate zombie wastelands, blasting boomers and slicing up screamers for the past couple of months. We love the game, but slaughtering hordes of Infected can get a bit repetitive. That’s why the chaps at valve announced the Survival Pack add-on last week. The update will add a new game mode, and two complete campaigns for versus. The best bit? It’s totally free. Keep an eye out for more updates, and zombies, on Steam.