I've spent a lot of time talking about the campaigns and the improved level designs, but it would be wrong for me to ignore the other new features in this sequel. There's now a far wider selection of firearms on offer, and while most of them stick rigidly to the templates drawn up by the original game's machine gun/shotgun/sniper rifle trio, you'll still be grateful for the slight differences on offer. You'll also occasionally get access to special ammo packs that let you fire incendiary or explosive rounds, and for really big bangs there's a rare grenade launcher - a toy that will cause massive arguments if used carelessly. The new melee weapons are far easier to wield effectively, and come in a variety of shapes and sizes. As a rule I find the "slice-y" choices like the chainsaw and katana to be more fun than the "bludgeon-y" picks like the guitar and frying pan, but to be honest they all do the same job - decimating the zombies at close range. Wielding a close-combat weapon prevents you from carrying a pistol, so you'll have to be a little bit more sparing with the ammo on your primary gun.
The final new pick-up, and arguably the oddest of the lot, is a defibrillator unit that can be used to bring recently-deceased colleagues back from the dead. In the games I played, most people seemed to be giving this a wide berth - perhaps because it prevents you from carrying an all-important medkit. Hopefully a few more charitable players will emerge as the online community swells, because in theory this could be a game-saving tactical device.
Naturally enough, the game's cadaverous forces have also gained a few new allies. Aside from the standard Infected, the five Special enemies from the first game have returned, and this time they're joined by three new monstrosities - The Charger, The Jockey and The Spitter . All three fit neatly enough into the game, particularly when you see how their special attacks can work together. Chargers and Jockeys both force survivors into helpless positions: the former dashes into people and then smashes them into the ground, while the latter "rides" people and steers them into nearby hazards. However, it's The Spitter who proves the most dangerous newcomer, with an area-of-effect acid attack that can swiftly decimate an ill-organised group.
A typical situation is that one survivor will be incapacitated, and as a friend rushes over to help them back up, a Spitter shows up and gobs all over the place. In seconds the rescuer's health is whittled down to nothing, resulting in a second incapacitation, while the original victim is killed outright. At this point you'll probably hurl your joypad or mouse and keyboard across the room and make a disparaging remark about your colleagues - most likely a two-word phrase that rhymes with "Mucking Boob".
Such frustration is perhaps one of the only real criticisms I have of Left 4 Dead 2 - and indeed of the series as a whole. There's something unique about the way you're constantly put under pressure by The Director - the neat AI system that remixes level design and enemy placement on the fly - but every once in a while I wish that he'd slow the pace down a bit. The Director's style certainly owes more to Zack Snyder than to George A Romero, and at times the action can seem a little too relentless for its own good. I like a challenge, and I like close-run fights, but I'm not such a big fan of being vomited on by a Boomer just seconds after I've been strangled by a Smoker. This is a notably harder game than its predecessor, and it can be frustrating when you're sent back to a checkpoint for the fourth time in a row.