Yes, Left 4 Dead 2 is coming out just one year after the original game hit the market. But zombie fans leery at buying what might be considered a simple "yearly upgrade" to the original should put those fears to rest.

Left 4 Dead was a cooperative game following four survivors of the zombie apocalypse who're trying to escape undead of all shapes and sizes. For the new sequel, the original team returns with four new survivors, a new location, more zombies, and some fixes and tweaks that address the shortcomings of the initial installment.

What really sets the Left 4 Dead games apart from the typical run-and-gun shooter is the adrenaline-filled cooperative gameplay. Players must work as a team to survive the oncoming undead hordes and defeat special infected foes.

Left 4 Dead 2 expands the cast of zombies with Spitter, who projectile-vomits puddles of acid; the Jockey, who jumps on characters' backs and directs them like a puppet; and the Charger, who runs directly into players and leaves them in a lot of pain.

While Left 4 Dead had a rather indiscriminate location, the locale here is definitely the American Southeast. Entire levels take place in New Orleans and Savannah, Georgia.

One of the biggest criticisms of Left 4 Dead was the short length of its missions. The original game included only four scenarios, each of which consisted of four to five levels. Left 4 Dead 2 includes five missions, each with not only more levels but larger ones that flow more cohesively from one to the other. These scenarios are completely standalone in nature, but there is a story progressing through them.

New weapons play a larger part than expected in making this second installment more fun. Melee weapons like the katana, chainsaw and baseball bat make fighting a blood-splattered and visceral experience. The "feel" of whacking a zombie with a baseball bat just seems more fun than emptying a submachine gun at a charging foe.

Multiplayer Left 4 Dead 2 is similarly expanded. Along with the familiar Versus and Survival modes, there's a new Scavenge mode. In it, players search the game maps for gasoline canisters used to power a portable generator to earn more time in the game's countdown timer.

Left 4 Dead 2 offers plenty of new content and enhancements to make it a great complement to the original.