Simple and satisfying co-op fun with a group of friends.
Story of Left 4 Dead is kept to a minimum. You take the role of one of four survivors in a city infected with a deadly virus that turns people into running zombies. Your only goal is to reach the transport point and get rescued. In order to succeed you need to do some serious co-op with your friends. Look and feel of the game has been done in a way that it reminds those classical zombie movies from the late 70's and 80's. All of this means that Left 4 Dead takes away all the unnecessary aspects and focuses on what it's all about: killing zombies with a bunch of friends.
Game's structure is simple, because it consists of four separate campaigns or "movies", each of them has four sections in them and the fifth one is Finale. There's no possibility to save anywhere, but since you get a checkpoint after each section that's not a problem in any way. It takes around 30 minutes all the way to 180 minutes to complete one campaign depending on your team's skill level and of course the difficulty level (Easy, Normal, Advanced and Expert).
Left 4 Dead uses that same Source Engine that Half-Life 2 did and in some ways it's starting to show its age. There are not that many details, but at the same time the physics are top notch and there can be SOO much stuff flying on screen at once and still the frame rate stays solid all the time. This trade-off has been worth it: I'll take a solid and smooth action over beautiful graphics any day. Each campaign has its own theme in terms of environments and lighting effects, so even if there's only four of them it still gives a nice variety in that otherwise VERY straight forward shooting action. Sound design is also great: zombies growl and howl in a way you want them and firing a gun feels like you're really firing a gun. Music on the other hand is not that memorable, but it doesn't hurt the package either.
Controls are simple: you can shoot, crouch, reload and melee with your weapon in hand, but that's about it. Your character moves smoothly and the animation is fantastically executed. Important thing is that you can give items to your team mate and also revive and heal him/her with your own med kit. Guns are only the basic stuff, but they'll do the job: shotgun, automatic rifle, pistol, pipe bomb, Molotov cocktail and so on.
Left 4 Dead has obviously been made for co-op game and it really shows: playing alone is boring and playing with an unco-operative friend will make things difficult for you. Choosing your partners is especially important, because friendly fire is always on. Action is always intense, because if you want to grab something to eat you can always "take a break" and the AI controlled bot will seamlessly take over until you return to play the game. Game can be played via 2-player split-creen or system link or through Xbox Live with up to three friends. Great addition is that you can choose to play with a split-screen and then invite two other players from Xbox Live to join you in that same game.
Enemy AI is different from other shooters of this type: the game makes things different, because one time the zombies will come from behind and other time from side. Sometimes those extra guns are placed here, but sometimes they are placed there. These random elements make each playthrough a very different and unique experience, which is a great feature adding more gameplay time to this otherwise very short game.
Army of Two was supposed to be the ultimate co-op game, but it wasn't. Fear not, because Left 4 Dead is that game. Best with friends and a total crap with random people or AI controlled bots.