They're bum rushing again; a cascade of gnawing, screaming, snarling, sicken bodies fly through every open crevasse of a charming little house that has become a barricade of fortitude against the undead.

All this because one of our token heroes made a last minute smash and grab for some ammo, broke up the typecast quartet, and was welcomed by a sludge of zombie pheromone vomit to the face.

If Half-Life and its sequel spelled the advent of the videogame sense of the cinematic, capturing the filmic while never using its exact form, then Left 4 Dead runs with developer Valve's legacy to uncultivated territory.

On the surface it's what you've come to expect, with perfectly placed spectacle and the crescendos in pace to match. But Left 4 Dead also takes that cinematic inheritance a logical step further, by slyly inserting an omniscient Director who puppeteers and schemes to abash your foursome's every cooperative move.

With the grizzled veteran, the biker dude, the spunky office worker and the pouty lipped college girl with a geeky edge, Valve makes no qualms that they're working with B-movie fluff here - this is the zombie apocalypse, after all. And it's because of such understated territory that the robotic game god, known as the AI Director, has free reign to form the experience to the actions of you and your three friends.

A plot twist is a pile of ammunition, Chekhov's gun is a conveniently placed pipe bomb found early on in a level, hopeful brevity is a health pack, and the antagonist is multiplied as a powerful flood of infected: bulbous Boomers, strapping Tanks, weeping Witches, wily Smokers, and vile hordes. These curls in action make up the panicked ups and downs of the unexpected.

Two, three, four times over and you'll still be pressed to anticipate how the AI overlord will orchestrate the proceedings with these tools of solace, destruction, and downright grief. And it all seems as though it's a sentient designer behind the pull of every string; sitting at a desk in the halls of Valve, plucking at your nerves.

But this means of artificial intelligence is, first and foremost, a tool. There is an overarching amassment of tension, which works entirely within the realm of the planned and scripted. The Director follows this lead, working the dynamic within the designed. For you, though, the lines are evaporated. In the thick of it all, you won't be thinking about the designer in the sky or the man behind the curtain, but rather only one question comes up, "how the hell do I survive?"

It's both a testament to unerring work with a novel technology, as well as Valve's continually sung ability to wrap you in their flare for cinema which, here, is undoubtedly set to replicate the moments of the finest horror flicks. However, Left 4 Dead's unassuming content is structured as four seemingly low-key movie plots: get to the rooftop, get to the docks, get to the airport, and get to the farmhouse. They're even presented as pulpy grindhouse movie posters, right before the level begins.

But the beauty of it all is found in looking at it as satirical smoke and mirrors; Valve's formula takes pedestrian plot that would kill a movie and transforms it through the very virtue of the interactive.

Plod on for a few minutes with the clichéd crew, smacking of stereotypical in-game speech, and it becomes secondary to the banter over the headsets. The screams of your buddies, in person or online, somehow never take you out of the experience, on the contrary; they envelop you further. With such variance and calamity, it becomes a game of roles. Not the overt utterances or look of your character, but your willingness to cooperate for the sustenance of the team, seeing as it pertains to your own survival, too.

There is simply push and pull; you can only keep up by keeping smart, and the devious Director offers only a pittance of help. Scouting, human bait, and observing the environment for potential safe spots are strategies planned out cooperatively, which become the only way to truly relish in this new definition of survival-horror, or even succeed for that matter.

The ultimate product is a zombie flick that's designed to poke fun at the clichés it intentionally evokes. Left 4 Dead ropes you into a world that's been done one hundred times over, and that's the point. The designer in the sky, that omniscient Director, watches closely with a never ending bag of plot twists and death tricks.

In a film, the lull after a zombie death swarm cues the approach of a scene with either eerie tension or restrained repose. But those rules don't apply to an experience that only aspires to prod the conventional. More PlayStation 3 News...