Left 4 Dead has a little something for everybody who is a fan of old-style FPS shoot'em ups.
You play as one of 4 survivors in a sort of post-Apocalyptic world that is overrun with the reanimated dead. A big tough biker-looking dude ironically named Francis, a grizzled Vietnam vet called Bill, a white shirt & tie guy with the name of Louis, and the obligatory hot babe who goes by Zoey. Your character can heal not only him/herself but other squadmates as well, with the one portable first-aid kit everyone packs. There are also bottles of pills scattered around the 4 levels you play on, but their healing power is considerably less than that of the big red Med Kits.
Weapons are your standard FPS loadout. Auto shotgun, M16 rifle, Uzi smg, and a scoped sniper rifle that appears to be a Ruger mini-14. There are ammo caches to be found throughout the maps, as well as weapons if you feel like swapping out one zombie shredder for another. I really wish there would have been more of a variety of firearms available, perhaps some unlockable guns with more firepower and even select fire or secondary modes (grenade launcher, anyone?) that would become available as your character advances through the mayhem.
The SP portion of the game is VERY short....it took me about 3-4 hours to complete all 4 maps, and each one culminates in a huge attack where you have to fend off the hordes before being rescued by some kind of motorized transport. These generally present the most challenge and were the parts of the game that I would sometimes have to replay to get through successfully.
Where L4D really shines is in the MP. You can do Co-Op or general Death Match type games playing with other, LIVE humans, against the Undead. Servers seem to be pretty active and plentiful, even almost a year after the title's release.
The only thing that keeps me from scoring Left 4 Dead much higher is the incredibly short SP campaign, coupled with so-so graphics ( though the main character modeling is very good) & the aforementioned scarcity of weapons variety. Fire and flame effect is also behind the curve for these times, as are explosions. Would have also been nice to see more destructible elements in the gameplay, such as cars that can be exploded with gunfire or grenades. With a little luck these shortcomings will be addressed in the soon-to-be released sequel, Left 4 Dead 2.
See you on the zombie killing grounds in the near future.