Eurogamer writes: Remember the last time someone tried to make an online co-op zombie shooter? I wouldn't blame you if you'd forgotten, because it was absolute arse, to be blunt. Capcom, of all people, managed to botch it up so spectacularly back in 2004 that the survival element of the horror was sheer toleration.
But despite the harrowing memories of Resident Evil Outbreak, it had some cracking ideas too good to leave in the dustbin of history: who couldn't be excited by the idea of an online four-player co-op game where you're working together to escape from a procession of marauding zombies? Evidently Turtle Rock and Valve loved the concept enough to try and do it properly - albeit with an execution which completely rejects the notion that survival horror should be slow, ponderous and lacking in ammo. Left 4 Dead is more of a noughties reinvention of zombie horror, infused with the terrifying athleticism of 28 Days Later's brand of undead.