Valve's original Left 4 Dead which released just one year ago was no doubt a unique co-operative experience for the seasoned FPS gamer - it was so good in fact that we even awarded it as our 2008 Game of the Year. The sequel which has recently released has certainly brought some concern amongst the L4D fan-base. More recently we've had some downloadable content for the original title, and with its fairly short campaign, users no doubt expected the original to be more expanded upon - even though playing through the game never resulted in the same experience thanks to the A.I Director.

Here we are then just one year on and Left 4 Dead 2 sits in our Xbox 360 tray, but does it have us falling head over heels for the co-operative zombie shooter once more, or rather does the sequel merely feel like the expansion we were all expecting of the original?

Gameplay:

The big question for some is 'what's different in the sequel?' While it feels, looks and otherwise plays like the original, there is quite a bit more added in terms of not only features, but gameplay as well. The two more obvious additions upon having some time with the game, or even the demo for that matter, is the change of scenery and the inclusion of some new toys to play and dismember the zombie horde with.

Left 4 Dead 2 shakes things up a bit by changing characters and location. This time around users will take control of Coach, Nick, Ellis and Rochelle. The four are more of a chatty South American bunch that offer up some humorous moments, which unlike the original adds a broader sense of personality whilst you move throughout the campaigns. While the sequel may be lacking a playable character that zombies and gamers alike would love to get their bloody or soaked mitts onto in the form of Zoey - Valve have otherwise certainly made some drastic changes and improvements to the game.

One of the more impactful additions here is the inclusion of melee weaponry, which replaces your standard pistol. More surprisingly though is just how effective these weapons can be compared to an AK-47 or Shotgun. Furthermore, the melee weapons which include a chainsaw (not unlimited), cricket and baseball bat, not forgetting the crow bar, which looks candidly familiar to one Gordon Freeman's; they're all strangely more satisfying to unleash than gunning down a horde of zombies. I think the reason I like the melee weapons so much is simply because of the improved gore in the game, it's possible to swipe a zombie's head off with a katana and see it go flying. The more satisfying, besides the chainsaw, is probably the baseball bat – you get that much needed crunch sound effect with it when wood meets that hollow zombie skull (double checks appointment with psychiatrist).

Now, hitting a Tank in the face with a frying pan won't do much good, so naturally firearms are still a must for the special infected. There's not a great deal of difference even though there's some new guns such as an AK47 and other sub-machine guns, they all pretty much react in the same way, which is fine for spray and praying because as Left 4 Dead typically goes, if you're shooting there's usually anywhere from 20-100 zombies in view. However, firearms can have upgrades in-game from a player picking up a crate of ammo and placing it down for others, this enables players to swap out their ammo for say example, incendiary ammo, which ignites your bullets into flames upon hitting a target. Another notable addition here is the ability to have increased accuracy as you can get a laser-sight attachment for all firearms, and this works well, and obviously it's sole purpose is just to look cool. Even more comedic is with the most stand out, and new weapon in the Grenade Launcher; even this can have a laser sight attached, and no doubt will be one of the survivor's most treasured weapons in not only the co-operative campaign but multiplayer as well.

There's of course some new additions to the zombie family, these include the likes of The Jockey, who is always up for a good laugh as he aims to jump on survivors heads and ride them around like his own personal transport. The Charger, which can easily be mistaken for a Tank at first glance, likes to charge at things – such as a survivor, and then proceeds to pummel their skull into the ground, and the Spitter - well you get the idea, although this is deadly toxic green stuff and will incapacitate a survivor in seconds.

There are some other minor nuances which change up the gameplay somewhat as well and offer up some choices over what you want to carry. For instance, carrying a defibrillator so that you can revive a dead survivor is always handy, but carrying this uses up your slot for the medic pack, meaning you can't heal yourself should you need to in a hurry. Speaking of a hurry, also available is an adrenaline shot which replaces the pain pills slot, and essentially enables the drugged player to manoeuvre about with great speed and throws up a saturated screen effect, all the more better for dodging special infected, and while it lasts, it even enables you to pick-up fellow survivors, or heal yourself within just a mere second or two.

That co-operative magic that captivated so many of us in Left 4 Dead has not been lost in vein here; in fact, while the setting and atmosphere might have changed, with the choice available to pick-up items - as described above - that can replace something as vital as a medic pack, it at least gives some players food for thought, to what is a fantastic co-operative romp. So long as you've got players who you can communicate with, even if you're doing 2-player split-screen and jump online with other players to replace the bots, then you're certain to have a blast no matter what game mode you're playing.

The L4D veterans that wish to tackle the zombie horde at full capacity, in Expert difficulty mode, can of course do so, although now you also have the option to enable Realism mode. No doubt this brings an even greater challenge when combined with the difficulty, and co-ordination is the order of the day as all in-game aids are disabled. No longer will you be able to see friendly survivors that wander around out of your field of vision, no longer will weapons or other items be highlighted for you. As a team you must decide when you need to run and gun, or search for items – and do it together or you're all going to die.

The A.I. Director 2.0 likes to play games with the survivors, much like the original, based on player performance the A.I. Director will decide when to spawn a horde of zombies or special infected, and with new ways to dispose of enemies, things can get hectic in a hurry. There's one campaign in particular where the A.I. Director can do its worst, and that's on the Hard Rain campaign. Not only does it have control over the spawning of zombies and special infected, but also based on player performance the invisible god of L4D2 can bring down a monsoon on you and your survivors, and make life very difficult indeed. If truth be told though, that one campaign was easily the stand out moment from the campaign – in comparison it makes the rest of the game seem rather weak, yet on the plus side due to this, it's all the more jaw-dropping for that reason the first time you experience it.

Graphics:

It's certainly difficult to differentiate the appearance of Left 4 Dead 2 when compared to it's original counterpart. While there's certainly a bigger variety of common infected zombies in the sequel and more gore and limbs to dismember thanks to the all new melee weapons, the biggest noticeable difference is really in the lighting. Most environments are well lit, some even taking place outdoors in the bright sunlight, which seems somewhat of an odd place for what one would consider a horror co-operative shooter, and does take away from the tension somewhat compared to the original. However, this all builds up to the Hard Rain campaign, which is dark, but not only does the A.I. Director have control of the infected here, but also the weather, it can nigh on be impossible to see when trekking through this flooded and rain struck and infected town. This is not only a major visual contrast to the rest of the game, but can offer up some rather exhilarating infected encounters.

Sound:

The audio effects and even the music used in-game, and especially on the various and amusing karaoke machines - everything simply meshes well together from a simple frying pan whack to the face, to revving up the chainsaw and charging down a narrow corridor with nothing but zombies, body parts, and blood insight - it sounds... wonderful. The biggest audio factor comes more from whom you're co-oping with over your headset, and you and them reacting and discussing what's going on on-screen.

Longevity:

While Left 4 Dead 2 certainly ranks in a lengthier campaign playthrough of that compared to the original, how much you ultimately play the game depends not only on your fondness of body dismemberment, but also the competitive multiplayer aspects as well. Make no mistake, the fleshy-meaty part where all zombie hell break loose is in the main campaign, and really should only be played in co-op for ultimate enjoyment and ultimately screams and laughs. That's not to say the the competitive aspect won't get players hooked though, in fact, while competitive, it's all co-operative goodness at the core. If you loved the original zombie infested title, then the sequel is absolutely the more complete experience.

It's rather amusing how sequels work, in regards to a comparison between this and the original, the L4D experience from both combined feels more like a series progression rather than a direct sequel, which would typically continue the story. This is no bad thing though, it's something rather unique to the gaming world and more reminds us of the odd workings of television series progression seen in series such as Lost or FlashForward, as opposed to a film sequel, the latter of which most developers typically strive for – which only brings yet more uniqueness to the Left 4 Dead saga.

Overall:

The co-operative and multiplayer experience of Left 4 Dead 2 is much like that of the original, but with some intriguing new modes of play. Ultimately though we feel we can only recommend Left 4 Dead 2 to the online community of Xbox Live (or those of you who play System Link), the co-operative experience is just that phenomenal and unpredictable when played with friends on various difficulties. Albeit offline users still have the ability to play via. two player split-screen (frame-rate can suffer somewhat though), which may be reason enough for purchase, but this is really one game to play all the way co-operatively and we wouldn't recommend it any other way. With this in mind we feel that Left 4 Dead 2 fails to capture all audiences and merely aims its sights at the online community, which is a shame as other games still manage to offer more encompassing gameplay experiences.

Co-operative games have begun seeing a rise in recent years, but there's something about the undead that makes for a great co-op experience, the last memorable title that springs to mind is the classic Doom 3 that had friends squealing like little girls over their headsets at the mere sight of a shadow. There's certainly been nothing this year to topple the experience of the original zombified experience that is Left 4 Dead, that was of course until the one year anniversary of the zombie apocalypse, and thus the rising of Valve's unmissable Left 4 Dead 2.