Valve, the out-there creators of the Half Life series and the mind-meltingly puzzling Portal, now brings you Left 4 Dead - a teamwork-centric zombie-apocalypse survival horror.
The game is split into four chapters, each a self-contained, five-part adventure. Each one puts you in a different locale - like a forest, city or airport - but with the same objective: fight to a rendezvous point so you can be evacuated.
The problem is that between you and the rendezvous point is an absolute shed-load of zombies, and these aren't the hands-straight-ahead shufflers of old-school horror. These are the run-really-bloody-fast-at-you-and-tear-you-to-pieces kind, made famous by films like 28 Days Later.
To make the task a little more manageable, you can invite three mates to give you a hand, and this is where Left 4 Dead really shines. The four of you have to be well-organized and level-headed to survive - stragglers and lone guns will simply get ripped to shreds.
Other than the safe-houses that book-end each chapter's five parts the action is almost entirely relentless thanks to The Director, an AI being that controls the flow of zombies and supplies in realtime.
Play the same level again and it will be a very different experience, with attacks coming at different moments and weapons not being where you remembered. This adds a huge level of re-playability - which is a good thing, as each chapter is only a couple of hours long.
Play as a zombie
If you ever do get bored, Left 4 Dead has an ace up its sleeve - you can play as a zombie. That's right, you and your mates can take on the role of zombie special units, from the super-tough Tank to the stealthy, leaping Hunter.
You then have to prevent four human survivors from getting to the end of the level. Believe us, it's a hell of a lot of fun.
Left 4 Dead’s only problem is its reliance on multi-player. Playing the game on your own is no fun at all, but providing you've got Xbox Live this is perhaps the greatest, most panic-inducing survival horror game ever to hit consoles.