Valve Software has an irritating habit of producing games that can quickly eat my time and soul: Half-Life, Team Fortress Classic, Counterstrike, Half-Life 2, Team Fortress 2, Portal. It would be difficult to count the number of hours I have put into Valve games.

This year’s assault on my free time is Left 4 Dead. Aside from the delicious pun, the cover art also tells you how many players the game requires for maximum fun (much like Army of Two did).

Left 4 Dead is a “multiplayer, co-operative, first person zombie apocalypse survival simulator”. Each word in that description is key to understanding the game and towards maximizing fun and killification. While the game can be played in single player mode, it is no where near as enjoyable, and was obviously designed for four (or more) players. In fact, the “Single Player” option on the main menu is the last option.

I’m going to go right ahead and say it:

If you don’t plan on playing this game with other people, don’t bother picking the game up.

The single player game probably only lasts 4 hours; 5 max. There are four “campaigns” (though I prefer to think of them as “movies” – they’re kind of designed that way, and even have posters). Each campaign takes a little over an hour to complete.

While the four campaigns have different settings (city, forest, suburb, airport), they have common checkpoints and plots: there are five parts. The first four end with reaching a “safe house” and the last one involves summoning a rescue vehicle via radio and then holding out until it arrives. Along the way, there will likely be one or two points of “hold out against the horde” as well.

The game is thin on plot but thick on atmosphere. It encourages co-operation between players in subtle but important ways. You can always tell where your teammates are, for example. You have to watch each other’s backs: some zombies can “pin” you, which requires another survivor to come to your aid. If a survivor is “incapacitated”, the others come as fast as possible to help their downed comrade because, seriously, if you lose a member of your party, you’re totally screwed.

Aside from the thousands of “horde” zombies, there are a few types of “Special Infected:”

• Hunter: These are fast, jumping zombies that can tackle and “pin” survivors while chopping them to ribbons.
• Smoker: These are slow zombies that can grab survivors with their extremely long, prehensile tongue. They then pull their prey in (also “pinning” the survivor).
• Boomer: Huge, fat, lumbering gasbags. They can vomit on survivors; doing so will summon the horde to attack those vomited upon.
• Tank: Huge, slow, extremely difficult to kill, and heavy damage. There will only be one per level (except the final hold-out period).
• Witch: Extremely powerful zombies, witches can typically kill with one blow. There is only one witch per level, and she sits, crying to herself. She is non-aggressive, and will only attack if startled (like, shining her flashlight in her eyes).

At first, I thought I might get bored with playing the same four campaigns. That they’d get predictable and thus easy. This is not the case. For example, the location of the Tank and Witch spawns (hell, all spawns, including ammo and health) change every play through. This adds to a degree of uncertainty and ensures freshness.

In addition to multi-player co-op, there is a multi-player “versus” mode. In this game, there are eight players: four survivors and four infected. Each team takes turns playing a side. When in “survivor” mode, the game plays like normal, but playing infected is a different game entirely.

When playing as an infected, the game AI chooses which type of special infected you will play: smoker, boomer, hunter, usually; once per level one player is chosen as a tank (players never spawn as witches). As an infected, you’re pretty much toast if someone shoots you even once (really, really low hit points), but you will continue to respawn until the survivors are all dead or in the safehouse.

Infected can go places players cannot (such as climbing to the tops of buildings). Since the infected team can communicate with one another, always know where the survivors are, and (when not ‘spawned’) move around the map freely, this allows for some awesome moments of co-ordination.

There is nothing more fun than a well-thought strike between a boomer, two smokers, and a hunter.

For those who are “Achievement” hunters, the game’s achievements are very achievement-y. There isn’t a lot of grinding for them. They are awarded for things like “headshot a hunter while he’s jumping” or “killing a tank with no one taking damage.” Hard things (there is one super-grind one, but it is more of an homage to Dead Rising: Zombie Genocidest requires that you kill a total of 53,595 zombies, one more than Dead Rising’s Zombie Genocider achievement).

It is a weird game. I’ve picked up the controller with the intent to simply play for ten minutes or so and found myself in a good group and then two hours later I’ve completed two campaigns.

I highly recommend it, especially as it isn’t going to be a “finish the story and be done” type of game. Unfortunately, I must say that playing it single player is an activity unworthy of your time (unless you want to learn the scenery).