WorthPlaying: "I'll admit that Left 4 Dead had me at "cooperative zombie survival first-person shooter for up to four players," but if the idea of working together as a team to get from point A to point B via a whole lot of Z doesn't do anything for you, you might be undead. Despite somewhat limited content on the campaign mode, it succeeds in two really important ways: recreating the fun, fear and superb panic induced chaos of fighting for your survival against zombie masses, and setting a new standard for cooperative gaming.
Valve has taken some liberties with zombie lore, and the first thing any self-respecting undead fan will notice is that these zombies aren't your traditional slowly shambling horde of Romero-style brain munchers. Instead, these are the psychotically rabid adrenaline junkies you might have seen in the movie "28 Days Later." In-game, they are known as the infected and much like ice cream, they come in many different flavors. The regular vanilla zombies are your slathering bullet sponges and will simply run at you wailing and attempt to rip off your head. Usually, they aren't a problem, but when they get together en masse, they are known as the horde and are both hideous and terrifying in their hyperactive brutality.
Then there are the super-infected. These undead have special powers that make them especially lethal. The Smoker has a tremendously long tongue that it uses to lasso and pull you toward it. The Boomer is a morbidly obese zombie with chronic indigestion whose primary weapon is putrid green stomach bile that he projectile-vomits on you with alarming accuracy. This has the effect of obscuring your vision and, as an added bonus, alerting the horde, which will inundate you like a dead flesh tidal wave."