I’ve only put a couple of hours in to Left 4 Dead, but I’ve had a lot of fun with it so far. In terms of gameplay, it’s the co-op shooter that the world has been waiting for — four players, which can be any combination of human or AI, fighting for survival against hordes of zombies across four unique campaigns. The zombies (or “Infected”) are more 28 Days Later than Dawn of the Dead, running, jumping, and climbing their way across the landscape rather than shuffling along. Beyond the anonymous hordes, there are a few super zombies as well, like the Boomer, which showers the survivors in horde-attracting bile by either vomiting on them or exploding nearby, and the Tank, which is huge and super-tough.
The co-op focus of the game is reinforced at every turn. Resources like pain pills and first aid kits are limited, so you have to share them around, and healing someone takes a few seconds, so you’ll need to provide cover to both the healer and the healee. Several enemy attacks can pin you down as well, so you need to rely on your buddies taking care of the offending zombie for you before you can get back up. If you run out of health and are knocked down, your teammates can revive you, but again, it takes time.
There are two other aspects of the game that help make it greater than the sum of its parts. The first is that the whole thing feels like a movie — the best way to put it is that it’s not a zombie apocalypse simulator, but a zombie apocalypse movie simulator. The graphics are starkly lit and awash with film grain, the music is full of subtle cues that clue you in on upcoming attacks, the origin of the zombies is left deliberately ambiguous, and even the four characters are your classic misfits: the tough biker guy, the IT worker, the Vietnam vet, and the horror-obsessed college girl.
The other is the Director, an AI that oversees the entire game. It wouldn’t be much of a zombie flick if you could memorise what was around every corner, so the Director mixes it up, changing the numbers and types of zombies and changing the locations of items and weapons on each play thorugh. It’s definitely not random, though — the Director makes its decisions on-the-fly, based on how you’ve been playing the game, and it does an excellent job of throwing just enough at you, so you can make it through by the skin of your teeth, just like a good zombie movie.