Check out the official release video and PR below.

Valve, creators of best-selling game franchises (such as Half-Life, Portal, Team Fortress, and Counter-Strike) and leading technologies (such as Steam and Source), today announced the first game add-on for its co-operative zombie thriller, Left 4 Dead 2 The Passing, is due for release Thursday, April 22 exclusively for the Xbox 360 and PC.

The first game add-on for Left 4 Dead 2 (L4D2) brings the original Left 4 Dead (L4D1) Survivors down south for a meeting with the L4D2 cast, while delivering new single-player, multiplayer and co-operative gameplay for  the PC and Xbox 360.

The Passing also introduces a series of weekly game mode events dubbed “Mutations.” These week-long runs of new gameplay modes range from “Realism Versus” mode to “Chainsaw Massacre,” which gives all players chainsaws with an unlimited supply of gasoline. There are over 20 Mutations planned, each playable on all L4D2 Campaigns. Mutations are exclusively available to owners of “The Passing” DLC.

In addition, “The Passing” offers a new co-operative challenge mode of play, support for infected bot play in Versus, a new “uncommon common” zombie class (the fallen survivor), melee weapon (golf club), and firearm (M-60).

Available for 560 Microsoft Points on Xbox 360 and free on the PC, “The Passing” takes place just after the Dead Center campaign of L4D2. Set in a small town in rural Georgia, players assume the role of the L4D2 Survivors as they meet with the L4D1 characters.

Hunter

Description: My personal favourite, this zombie is small, agile and vicious. He works by crouching, then leaping at you and ripping out your innards. He can quickly incapacitate an unknowing survivor. However, he has a fairly limited amount of health and can be shot off his victim with ease.

Versus tactics: Don’t bother using this Special on anyone in a pair or larger group, as you will only be able to deal a pitiful amount of damage before being killed. Instead, try to ambush a straggler or someone far ahead. Make them realise that L4D2 is not a game for would-be Rambo’s…

Recommended weapons: Since the Hunter has such a small amount of health, anything will do. However, in order to avoid accidentaly hitting the survivor pinned underneath him use a accurate weapon, or fire in small bursts at him. The grenade launcher is therefore not recommended.

Smoker

Description: The smoker is another deadly, but fragile Special Infected. He is definitely the ugliest, sporting a number of large boils off the side of his head, but unfortunately those don’t offer any extra protection from bullets. A quick burst is all that is necessary. The smoker operates by snaking out his long tongue at unsuspecting survivors and pulling them towards him, either constricting them against a fence or other obstacle, or reeling them towards him where he can deal extra damage by slicing at him.

Versus tactics: Again, this zombie is most effective when targeting a lone wolf. As the smoker’s tongue is very fragile, try to get into a position where you can reel your prey in all the way, or your tongue may be simply cut off.

Recommended weapons: Anything is good against this guy, but during Versus they tend to operate from dark corners or from up high, so a hunting rifle or sniper is the best for most of these situations.

Spitter

Description: This tall, gangly, apparently female zombie can spit out large piles of acid goo onto groups of survivors. The goo is very effective at lighting fuel cans on fire as well, and this can be used to your advantage during Scavenger. Again, the main traits are a lack of health but a lot of potential damage.

Versus tactics: Unlike the previous two, this zombie’s special ability is best used on large groups of survivors. If you find a small bottleneck, the acid can delay their progress for a few seconds, allowing other infected precious time to strike.

Recommended weapons: In versus, these guys can be a real pain, as they typically go high above you and shoot goo down on your head. Your best bet is the sniper.

Boomer

Description: The weakest of all the Special infected, yet the Boomer is a huge asset to any Infected team, but he lacks direct damage. The Boomer operates by vomiting boomer bile all over a group of survivors, which attracts the Horde and makes them hone in on anyone covered in the dreaded bile. However, the Boomer is easily taken care of.

Versus tactics: Don’t expect to survive for long as a Boomer due to his lack of health. However, boomer’s will explode in a pile of bile if killed, so try to run at a large group of survivors when they aren’t looking and do a little Kamikaze.

Recommended weapons: Don’t bother wasting precious assualt rifle or heavy weapon ammo on this guy. A few shots from the magnum should do the trick just fine.

Jockey

Description: The Jockey is quickly becoming a favourite with Versus players, and for good reason. The Jockey’s ability to jump on the back of any survivor and drag him in whichever direction he desires makes him a valuble part of an Infected team. He is quick, agile, and can take a surprising number of hits before going down.

Versus tactics: The best way to use a Jockey is when there are ledges. High ledges. On more than one occasion, there is an oppurtunity to jump on a survivor’s back and make him run off the edge of a parapet, to a frustratingly quick death.

Recommended weapons: The Jockey boasts slightly more health than some of the other Specials, but try and place your shots to avoid hitting the survivor underneath him. An assualt rifle with quick bursts is best.

Charger

Description: With a big build and a massive right arm, the Charger can take a heck of a beating as well as deliver one. This Special is especially good at taking down cramped groups of survivors, so watch those corners! He also requires something with a bit of ‘umpf’ to take down. His major weakness however, is that if he charges and the survivors manage to dodge him, he will smack into any obstactle which will stagger him for several seconds, allowing you to get in those precious shots.

Versus tactics: The charger acts by, yep, you guessed it, charging at survivors. He then grabs one and pounds him into the floor. Pleasant, huh? The best time to use the charger is down long corridors where you can knock down an entire team and deal some punishing blows in one foul swoop.

Recommended weapons: The Charger has a fair amount of health, but he is also a big target. The best weapon is a shotgun or assualt rifle.

Tank

Description: The big daddy of them all is the Tank. He can scatter whole teams, incapacitate you in seconds and throw chunks of pavement at you. This guy is the biggest Special in the game, and requires some military style teamwork and a healthy arsenal of big guns to take down.

Versus tactics: If you are lucky enough to be chosen to play the tank, then there are a few pointers that you should take heed of. One, is that you will cease to play the Tank if you don’t go on the offensive. No camping! The second is that you shouldn’t try to run after healthy survivors. They move at the same pace as you, so you will never catch up. Instead, target any survivor with a low health and a limp, and focus on him until he is dead or incapacitated. Then repeat the process while the other Specials take out the rest of the team.

Recommended weapons: Anything and everything. The biggest gun you have.

Witch

Description: If the Tank is the big daddy of special zombies, then the Witch is the big momma. She is small, surprisingly so, but can incapacitate you with one swipe on the higher difficulty levels. Her size makes her a very difficult target and she is the fastest Special zombie in the game. She can, however, be avoided if you don’t make too much of a rucus as you go near her. Turn off your flashlights, and don’t shoot! She cannot be played as in Versus.

Recommended weapons: Like the tank, everything you have.

Well that’s all folks! I hope you leave now with some new knowledge on the Special Infected in Left4Dead 2!

Firstly, let me just say this; it’s not an expansion to L4D. So you folks can rest assured that when you fork out for this game, you aren’t handing over you hard-earned cash for a rehash of the original. Now of course being a demo, I was not able to see all the different features of the game, but nevertheless, with the official release date less than 3 weeks away this is very close to the real thing.

The demo allows you to play through 2 missions of the first level in the game, “The Parish”. The demo opens with your team having just stepped off a boat, and the driver mutters something about finding other survivors, then leaves. From hereon, you are on your own! In typical L4D style, there is a table with a small assortment of lower tier weapons; SMG’s, shotguns and some healthpacks. After grabbing these, it’s off to fight in an urban maze of houses and allyways.

Something that struck me in just the first 5 minutes of playing was the visuals. Now, L4D2 is built off the Source 2 engine, just like the last game, so I wasn’t expecting much in way of improvements. However, the character models are now more detailed, the weapons look sharper, the lighting effects look even better and the visuals have been generally shrapened up across the board. The improved visual effects don’t stop there. No, the most noticeable visual addition to Valve’s latest is the gore, and more specifically, the ways in which you can blow zombie’s to bits. Whereas in the last game where zombie mutilation was limited to say the least, in this game you can blow off arms, legs, heads. You can tear open stomachs and see some zombie ribs. You can blast the undead in the back if you want a sight of their spine. Make no mistake, this is one gory game.

Melee weapons are one of the major features of L4D2, and they are great fun to use. I couldn’t find the oh so coveted guitar, but I did get a chance to try out the nightstick, the frying pan and the machete. The machete was the most fun to use, as you could lop off zombie’s heads in one swing. Not to be unfair, the frying pan delivers one mean whack, and the sound of a clean blow is immensly satisfying. There are a few other new arrivals in the weapon department; the silenced SMG, the auto shotgun and the sniper rifle (don’t worry, the hunting rifle’s still there). They’re all welcome additions to the somewhat limited arsenal in the previous game.

The new boss zombies were also good enough to put in an appearance in the demo. Along with the old favourites, (the Tank, the Witch, the Smoker, the Boomer and the Hunter) I was lucky enough to be half killed by the Charger, the Spitter and the Jockey. The Charger is like a minature Tank; he is big, strong and deals out a lot of damge by sprinting at the nearest player and grabbing their faces to pummel them into the ground. Pleasant, I know!  The Spitter is a slowish, lanky zombie. He spits up giant piles of acid goo, and if you step in it for too long, your health will shoot down. They are very effective at blocking choke points. And finally, the Jockey, my favourite. He is very fast, but not very strong and it does not take much to put him down. However, he works by jumping on a player and takes over control of you. He will normally steer you into the path of other super zombies, or into a big crowd of infected. He is great at taking out corner campers, so keep moving!

Well I hope that this has whet your appetite for more Left4Dead2 action. And just for the record, the answer to the question, “Should I buy it?”- well if you are on the fence at the moment, is most definitely a resounding yes.

The L4D2 demo is available to anyone who pre-ordered the game through Steam or other participating retailers. The demo because avilable to everyone on the 2nd of November, and the full game is released on the 20th November.