Just go on without me!" I shout. I'm pinned to the ground, a swarm of infected stamping on me. I fire blindly into the crowd, trying to help another survivor who's being tongued to death. A stray bullet severs the lengthy, constricting tongue and he runs for the safe house. Someone is in there already, waiting by the door. Norman, I think. Just like him to get away. As I'm overwhelmed the safe house door is closed. BLAMMO, BANG. "DIE YOU ZOMBIE BASTARDS!" Level over.
Yes, I said "level". For a moment there I was in an '80s action movie, sacrificing my life so that others could live. Left 4 Dead does that to you. It's an entirely new way of playing games with friends. You and up to three others battle through one of four movie-inspired apocalyptic backdrops, trying to reach safety, and that generates war stories like nothing else I've played. With four players working together against the overwhelming odds, plans are born out of desperation, some meagre supplies and a lot of luck.
My companions for my Left 4 Dead review were Norman Chan, Dan Stapleton and Evan Lahti of PC Gamer US. Which is handy, because at the start of every level there are always four of you. You can choose a biker, a pretty girl, an office worker or an old man. It makes no difference as they're all created equal and only there to differentiate between you and the zombies. The weapon choice is meagre: you get a pistol, a healthpack and either a shotgun, a rifle or an automatic weapon.
Along the way you'll find a few pick-ups, such as Molotov cocktails or pipe-bombs, as well as such environmental weapons as gas canisters and petrol tanks. You can play on your own, with three AI team-mates, but I'd suggest you seek out companionship. Even having one other human there makes all the difference, and with a full complement of friends L4D is absolutely extraordinary.
It's knowing you can scream for help and someone will come running that makes this game so compelling. Co-operative play is not just about having people on the same server: it's about sticking together and maintaining communication.
How many games have you played where a jittery group of four people are creeping through a hospital, reporting cleared rooms, checking on each other's state of health and ammo counts, the front two duck-walking so the two behind can fire over their heads? If someone falls behind, the team slows down. If someone gets too far ahead, you beg them to be more careful. In L4D your strength relies on the person beside you. You need to be able to call on that person at any time.
All this takes place in a world of perpetual night, so in debt to cinema clichés that the levels load with faux movie posters and the end credits point out how many zombies were "harmed in this production". The four missions take from between one and two hours each to complete, depending on the difficulty mode. You fight through a hospital, a forest, an airport and farmland. You hide in shacks, traipse through sewers, scurry over rooftops, shoot up offices and make dramatic last stands.
The backstory is told through graffiti on the walls: warnings from the people who went ahead of you, messages to loved ones, zombie death counts, conspiracy theories. Aside from an incredible opening movie, Valve use the techniques used in Portal and Half-Life 2, where the scribbling on a wall leaves you with an uneasy feeling about what's gone before. The settings are often mundane locations, but covered with blood, full of corpses and replete with dark corners for bosses and zombies to spawn in.