When you put Valve and Turtle Rock studios together in one place you're going to get something pretty special out of it. In this case it's like the holy amalgam of peanut butter and chocolate, a tasty treat that's sweet but also chewy. In video game terms I'm talking about the zombie survival horror first person shooter: Left4Dead.
You and a few other survivors are immune to a virus-like infection that manages to turn the rest of the population into blood and flesh-crazed zombie-like monsters. These monsters are hell-bent on snacking on the populace that remains and survivors must attempt to get from a starting location to a pre-determined end point in 4 decent sized campaigns spread out over 5 missions per campaign.
The game doesn't have a cinematic story mode; you have very little in the way of story/background to get into. This is good old fashioned zombie shooting action the way that it was meant to be done. A slight cut-scene begins the campaign and a small one ends it, everything rolls with credits (the credits being full of game stats) and that's about it in terms of story.
You have four archetypal zombie horror survivors that have no discernable in-game statistical advantage, presumably so Valve and TR could keep the game's balance fairly in check regarding the survivors.
Bill is the ex 'Nam vet who is fighting a new war against a soulless enemy.
Louis is the disgruntled office worker who is just trying to survive.
Francis is the hard-bitten biker dude with tattoos and a loud mouth.
Zoey is the hot college girl who manages to be sensible and tougher than she looks.
Left4Dead works well as a pick-up and play game, it's easy enough to learn the controls and Valve have made sure that the console version is just as good as the PC game in terms of playability and design. You can carry one extra weapon and you always have a pistol (with infinite ammo) as a sidearm. There is a shotgun, assault rifle, sniper rifle, machine pistol and a few grenade types (pipe bomb and molotovs) to choose from.
Each player is allowed one bottle of pain pills and one health pack.
Left4Dead fills non-human player spots with AI and allows you to play offline (via split-screen) or online, cooperatively or via adversarial matches with friends or strangers over Xbox Live. This is one of the true cooperative gameplay experiences that I've come across in a long time. I can't sing the praises of this kind of game or gameplay enough; being able to battle against the AI (or other human players) with up to 3 other friends is something that other developers need to take note of.
Valve have managed to mix in cooperation even in versus mode (discussed later on) and they've crafted an addictive blend of adrenaline fuelled gameplay to go with it. Whilst you can shoot the enemy with your friends, the true cooperation comes from being able to pull them up if they get knocked over the side of a building, give them pill bottles or even heal them if they're too badly injured. You're going to need to work together as well, since the AI has a habit of doing just that against you.
A Smoker will drag off a team mate so they can be pounced on by a Hunter, or vomited on by a Boomer. When a Tank appears, you will often need every gun in your rag-tag group of friends to survive, because they are true engines of destruction.