Left 4 Dead

Left 4 Dead, the new co-operative shooter from the makers of Half-Life and Portal, comes down on the fast side of the zombie speed debate. And it's about time sprinting ghouls had their shot in videogames. George Romero traditionalists may balk, but running ghouls work well in the context of consoles. Shooters depend on forward momentum: Allow players to linger too long, and they obsessively scour every nook for bullets and health boosters. In Left 4 Dead, there's no such thing as a clean room: Hang around, and the game's "director" will throw more zombies at you. And when dozens of undead tweakers come booking at you from the darkness, it's hard not pull a Cosby—first you say the expletive, then you fill your shorts with the stuff.

Left 4 Dead recreates the trajectories of four zombie-movie plots, each ending in a dramatic escape. Players make their way through infested sewers, abandoned hospital corridors, and a ruined airport, fending off brain-eaters at every turn. Each finale calls for the survivors, by now low on health and on their last nerve, to hunker down and defend a position while waiting for their airlift. That's when the game really pulls out the stops, unleashing an army of the dead. Peppered throughout these undead attacks come encounters with mutated varieties of the zombie. On paper, the Witch, Boomer, Tank, Hunter, and Smoker seem like cheesy videogame iterations of the traditional reanimated corpse. But each of these formidable creatures is grounded just enough that they seem to fit the milieu.

Beyond the game: Long after Team Fortress 2 launched, Valve continued to support the game, giving players new weapons, characters, and maps for free. Expect them to take the same long-term approach with Left 4 Dead.

Worth playing for: Co-op is the new deathmatch. Left 4 Dead demands that players work together, but in the last seconds when that chopper is on the pad, self-preservation frequently trumps teamwork.

Frustration sets in when: If you aren't playing with other humans, you're doing it wrong. The game will provide computer-controlled 'bots to fill out your party, but they play too conservatively. Left 4 Dead is one of the rare cases in gaming where human error makes the game more fun.

Final judgment: A redefining moment for the survival-horror genre.