Sure, I complain a lot about zombies and zombie-related entertainment around here, but few things are as gratifying as blasting their mealy heads to kingdom come in Left 4 Dead and its sequel. If you haven't played it, allow me to rave for a second. It's pure, unadulterated video game adrenaline. You'll scream, run, and grit your teeth. It provides a visceral experience more engaging and heart pounding than just about any undead flick. The premise is simple - you, along with 3 other survivors, have to make your way from safe house to safe house, all the while dodging and shooting flesh eating horrors.

In the first excursion into the apocalyptic pandemic, we're introduced to Francis, Bill, Zoey, and Louis. They're a motley group thrown together with little explanation of their back story. But through their repartee, you immerse yourself in their desperate dynamic and become attached to them. In the sequel, it's the same recipe, but with different players: Coach, Rochelle, Ellis, and Nick.

Now, with the newly released downloadable content, we'll get the opportunity to play the lot of them as they meet up in 'the Passing'. Available only on the XBox 360 and the PC, it's not only going to offer up the original quartet of characters, but a plethora of new gameplay options. In this three-map expansion set between the "Dead Center" and "Dark Carnival" levels of L4D2, we're introduced to the "Mutations" mode of play, which alters the rules on a weekly basis. This generates such variants as the "Realism Versus" mode, or "Chainsaw Massacre", where each player is equipped with a chainsaw with a limitless fuel supply. You'll also get to go head to head with a 'Fallen Survivor', a new enemy who may drop useful items. The game was already robust in its original release, but now, for 560 Microsoft points, this injects some new life into it.

Past the jump is a fun little cutscene between Rochelle and Francis.