If you’re new to the series, the basic goal of Left 4 Dead 2 is for you and your three fellow players (or somewhat competent AI bots if playing alone) to battle your way through masses of Infected to reach a safe house. Safe houses allow you to catch your breath and restock on supplies like ammo and health packs before you set out for the next leg of your campaign. A campaign is made up of five levels and by making it to a safe house, you’ll move onto the next level. Certain levels require that you and your team hold out at an area and fend off enemies for a certain time. These “finales” are big events that culminate in large swarms of Infected attacking while you complete predefined objectives. One mission has you actively collecting gas cans to fill a getaway car; another has you hold out while transport arrives. The finales this time around are much more engaging and offer a fair amount of challenge compared to the first game. Those on the PC can play the campaign with bots, online friends, or with complete strangers; the entire matchmaking process has, in my experience, been smooth and other players were found rather quickly.

So what’s an Infected? It’s a “zombie” more akin to those found in 28 Days Later than in work like Romero\'s Dawn of the Dead. You won’t find any zombies shuffling towards you here though. When the Infected notice you, they’ll sprint in your direction, even climbing and hurdling over obstacles or leaning into turns to reach you faster. While they are relatively weak, they make up for it with numbers. And by numbers, I’m talking over a thousand to two-thousand dead by the time a campaign’s finished. But it’s not just the normal Infected you have to worry about; there are also special Infected. The standard Boomer, Smoker, and Hunter all return, but with them come a few new faces. The Charger, who can tackle one player and knock back the rest as he rushes by; the Spitter, which utilizes a powerful room-clearing acid attack; and the Jockey, a pint-sized mutant who latches onto a survivor and pulls them away from the team into a group of Infected. Also returning from the first game are the Witch (who you shouldn\'t mess with), and the Tank (who you\'ll love to hate).

To help speed these Infected and the meaner special varieties into the afterlife, your arsenal now includes a plethora of new toys, some of which include melee options. Expect to see a katana, fire axe, crowbar (thanks, Valve), frying pan, and even a cricket bat lying around. The melee choices replace the standard pistol, but the trade-off in hearing Infected go splat and mowing your way through a crowd in a few swipes make it worth it. Military weapons like the AK-47 and SCAR show up in the campaigns, as does new Incendiary and Explosive ammo. Those disappointed in Left 4 Dead’s paltry weapon selection will find a lot of options here.

Much like the first game, Valve has an AI “Director” in place who will either ramp up or tone down the amount of pressure your team is under depending on how you well you play. If you’re getting a lot of friendly-fire and someone’s dying, the game will ease up on the Infected and give you enough space and trickle in enemies. If you’re doing well, expect more enemies, special Infected attacks, and fewer supplies in the environment. The Director will also mix up where enemies and supplies spawn every time you play, which makes this one of the series strengths. You can blast through all the campaigns in about a day or two, but playing through a second time will always give you a different experience. This, coupled with the game\'s various modes and difficulties, offers a lot of bang for your buck with replayability.

So besides Campaign, what other modes does the game come with? There’s Versus, which is basically a Campaign with four players trying to reach the end while four enemy players take turns as the special Infected whose main goal is to incapacitate and kill the other team. After each level, the teams are switched with the survivors now playing as Infected and vice versa. The team with the highest score (determined by how far the teams actually go distance-wise) wins.

There’s Realism, a Campaign mode that offers a more realistic experience to those wanting a harder challenge. Infected are harder to take down, require more shots, and Witches can one-shot a player. No player outlines are visible, so if you get dragged away by a Smoker into an alley, it is likely your team won’t hear or see you until it’s too late. Versus Realism is also available to those looking to really test their mettle.

The two other modes include Survival, which is a time-based last stand where the main goal is to outlast the clock on a certain section of a level. Scavenge is the other mode, which plays a lot like Versus but requires one team to grab gas cans to fill up a generator. The team with the most cans after three rounds wins. I personally enjoy this mode the most since it’s a quick competitive game that takes about ten minutes compared to the forty-five minutes with Versus. Valve has recently been offering quick updates for Left 4 Dead 2 called Mutations. Every week the Mutation mode will have a certain restriction that radically changes the game, whether it’s melee-only in the Campaign, or all of the special Infected in Versus are Tanks.

The game visuals have gotten a fine upgrade, in more ways than one. Several campaigns take place all throughout the day, character models and special Infected are more detailed, and enemies are more diverse. The most impressive change would be the gore and animations. Infected have multiple layers for their damage model, this means different attacks will reveal muscle, bone, and more gore. Valve added a large number of different wounds, so you may see the spine of an enemy from a shotgun blast, one Infected looking down to see intestine fall out of his own body from a rifle shot, and yet another hitting you with one arm because the other was removed in a gunfight. Like previously stated, the effects can be over the top, but they are an excellent move towards realism. Weather effects have also been added, which suffice it to say makes the Hard Rain campaign absolutely stunning.

When making sense of this fictional world, Valve has left a few bread crumbs along the way that help tie up the story.  Safe rooms will usually have messages and notes scrawled across the walls, almost as if it’s a public journal. The messages both relay personal information to friends and family about where their loved ones are heading to next; others share a person’s view on the situation (some fairly humorous).

Contrasted with the first game, the characters and campaign have a much stronger continuity this time around. The characters are total strangers who bond over time or generalize the special Infected in the first moments of the game before settling on a name (e.g. “tongue guy” and then “Smoker”). It’s nice to see Valve allowing the group to evolve as one plays, as well as having a logical progression throughout the campaign. Where Left 4 Dead put the survivors in a random situation and had them escape, Left 4 Dead 2 takes a note from Half-Life 2 and connects the story piece by piece. The hotel roof you start on leads to a shopping mall, mall to the highway, etc.; it’s mostly a seamless experience that involves the Southern culture and locales to various degrees.

Left 4 Dead 2 is what the first Left 4 Dead should’ve been: a tight and well executed package that offers a challenging spin on the zombie genre. Fans of the first L4D should make the switch to the sequel if they haven’t already; the additions to the core game are not that radical, but they are welcomed and feel fresh enough to warrant a purchase. And now with the recent content updates (including support for Mac), you’re getting extra value for free. Xbox 360 players still have to pay for The Passing/Sacrifice, however.

Again, this game easily earns its M-rating, and I cannot recommend it to younger teens or those who object to this kind of content. It is a blood bath, especially when using melee weapons, and the language can be a bit excessive at times. For those looking for a tame co-operative game, this is definitely not it. But for folks who are used to such content in their games, Left 4 Dead 2 is a solid and rather original FPS choice. I\'ve enjoyed it immensely and I’m sure you would too regardless of which version you pick up.

-- Jonathan “Keero” Harling