Undead Nightmare is one of those games that, when played in a busy office, can act as a Weapon of Mass Disruption. For starters, there's the odd spectacle of zombies swarming all over Rockstar San Diego's carefully constructed Western wilderness, disrupting the cut-scenes and generally making a mess of things. Then there's the utter racket made by the undead hoards - the wails and howls boxers-browning shrieks that attract people from the adjacent room. The occasional frustrated yell adds to the disturbance, but that's nothing compared to the excitement that greets the arrival of a rare mythical creature. "WHAT THE ***K IS THAT?! Is it... wait... no! Can I ride it? I can ride it! And it's on fire!"
Thankfully for the rest of the staff here, I've now finished my battle against the plague-ridden denizens of New Austin. The fight took a surprisingly long time to finish, however - far longer than what you might expect from an 800 MS point / £7.99 piece of DLC. Undead Nightmare gives you an awful lot for your money: a new single player campaign that will take five to six hours to wrap up, a quartet of fresh weapons, and a long list side quests and challenges to complete. After you're done with all this, there's new multiplayer material to get to grips with: the territory-snatching Land Grab match-type, and a co-op mode called Undead Overrun - essentially a zombie-based variant of Gears of War 2's Horde, pitching four human survivors against 10 waves of re-animated nasties.
Aside from the volume of additions, the impressive thing about Undead Nightmare is its sheer thoroughness. Rather than going for the easy money, and perhaps just lobbing a few new enemies into the existing framework, Rockstar has opted to completely overhaul the Red Dead experience in fine detail. So alongside the new quests, foes and weapons - the kind of thing you expect from a typical expansion pack - the developers have changed the whole appearance of their world, redressing the land in gloomy hues. There's a revamped soundtrack too, including a few licensed psychobilly tunes and even new cheeky comments for Marston himself as he loots the bodies of his rotten opposition.
As detailed in the preview we ran earlier this month, Undead Nightmare finds 'reformed' outlaw John Marston attempting to stop a mystery plague that's giving everyone a serious case of the brain-munchies. Right from the word go, when the slimy voice of a Vincent Price sound-alike sets the story in motion, it's clear that Rockstar is out to have a bit of a laugh. The ensuing story ends up revisiting most of Redemption's principal cast, and in most cases the accompanying cut-scenes are genuinely laugh out loud funny. In addition to mocking B-movie conventions, this expansion is more than happy to send up the more serious moments of the original game. Racist shopkeeper Herbert Moon, for example, blames the zombie outbreak on a British Catholic homosexual conspiracy.
As amusing as it is to see Rockstar subverting its own hard work, it's the changes to gameplay that really make Undead Nightmare so refreshing. Long-range gunplay is swapped out for a frantic riff on classic survival horror: ammunition is limited, and your swarming opponents will absorb bullet unless you aim for the head. John's slow-motion Dead Eye ability becomes an absolute lifesaver, but since your meter invariably depletes before you've despatched a fraction of your opponents, most large-scale battles become tense, hard-fought affairs. Of the new weapons, the Blunderbuss stands out as a clear favourite: a slow-firing cannon of explosive, giblet-raining doom. To reload this beast you'll need to harvest shrapnel from downed zombies - their ribs, ears and tongues - and as I described in the preview, this mechanic ends up having a fairly significant effect on the way you approach each fight.