Remember the good old days when zombies were more prone to shuffling than sprinting? Those days are over if movies like 28 Days Later and Valve's new PC co-op shooter Left 4 Dead have anything to say about it.

At EA's recent summer event, we saw the speedy undead in action in four-player co-op mode, where four survivors race from safehouse to safehouse, leaving hundreds of zombie corpses in their tracks. The foursome must survive five different scenarios – roughly 45 minutes each -- ending with a dramatic rescue on a hospital rooftop.

Each scenario starts out at a safehouse where you can fill up on health and ammo before battling wave after wave of the Infected. The foursome then venture forward, weaving through a series of abandoned buildings, dark alleys and underground tunnels to complete their next objective. One second everything seems calm and quiet, the next second the zombie herds descend on you like wild dogs in a steak factory. Our trusty machine gun did its due diligence for zombies coming at the front of us, and a melee attack came in handy for those that attacked us from behind.

Just like your gym coach always taught you -- there's no "I" in "team." Left 4 Dead is built around cooperative play and if you decide to go maverick then your chances of survival go from 80% to 20%. Venture too far from the others -- the game will prompt you to "stick together" lest you find yourself surrounded and eaten alive by a giant pack of zombies. Fortunately if your character or friends go down for the count, your teammates are prompted to come revive you. That's a good and bad thing. Cooperative pals will come heal you right away or you might be stuck, immobile, using your gun to shoot down oncoming zombies in a last stand. You'll also have plenty of chances to return the favor -- and healing pals while fighting off zombies adds to the overall tension in the game. Another interesting element in the game -- the better your group works together, the faster and more dramatic the action will play out.

In the demo, there was plenty of ammo available, so there were few instances where we were stuck a la Resident Evil, with loads of zombies and no way to kill them. You'll start out with basic weapons and can pick up more advanced guns (like an automatic shotgun, semi-auto rifle with scope, etc.) throughout the levels, which is highly recommended as you start to battle the special breed as the Infected, such as The Boomer -- a hugely fat zombie who projectile vomits and explodes when they does, The Hunter -- fast-moving monsters that can jump and climb walls and the Tank – another supersized zombie that hurls cars and other large, heavy objects and requires major teamwork to take down. We didn't run across a Witch (one of the strongest zombies, who can take you out with one attack) or a Smoker (a zombie with the ability to blur vision with black smoke and hold you down with it's whip-like tongue), but those are formidable foes. Our demoer recommended that if you see a witch, try to sneak away before it sees you -- because once those are in action, they're hard to take down.

Dude, buy a tube of Noxema.

Left 4 Dead isn't exactly a deep game, but it's a whole helluva lot of fun to play. When choosing between this game and, say, Resident Evil 5, it will be a tough call to make.