Left 4 Dead is my all time favorite zombie survival game. The simple mechanics of the gameplay and the increasing ramp of difficulty is well balanced in my personal opinion. It's great for a 20 minute gaming session on Normal, and up to two hours on Expert.

But my favorite way to play is on the original campaign, but in Left 4 Dead 2. More monsters, more weapons and, best of all, harder zombies.

IF you're willing to deal with the bugs, the lag, and the hackers, THEN this is decent free-to-play version of multiplayer cops and robbers.

Until the servers are upgraded, and the serve-side FPS and other such issues are completely ironed out, it will always be a slightly enjoyable, rage-building experience.

Some of the hairiest and most satisfying team co-ordination hassles are this game provides at the low, low, low, one time price of $0.00.

The gameplay is consistent enough to not be entirely frustrating, yet deep enough to give you the satisfaction of learning the ins and outs of combat. Diving under massed hunters' fire to bring them all to a flamethrower alien BBQ has never been better.

It's well worth the time it takes to download.