Left 4 Dead 2

Away from the co-op campaigns, Valve improves the competitive Versus mode, where four survivors play against four players alternating between special infected types. There's the long-awaited addition of four-versus-four matchmaking, and if you're playing as infected the heads-up display now shows you your team-mates' cooldown timers (both features are available for L4D1 in a patch, too). The new specials fit in perfectly, and do a better job of encouraging teamplay with their complementary attacks.

There's still no answer for people who want to be able to practice as specials before playing competitively, but there is a new mode called Scavenge, where survivors gather fuel cans to a generator to try and extend each round. A team of specials tries to stop them, and roles are then reversed. Unlike the throwaway Survival mode, where the idea is to survive as long as possible in a certain area, this one has real legs, which you'll probably still be shooting off one another in a few months' time. After its first multiplayer shooter was criticised for being too short, it's as though Valve chose to respond by, er, adding a multiplayer mode.

All good then? Not entirely. With the addition of Realism mode for people who want to be really challenged, there's an argument that the co-op campaign could be a bit more forgiving with respawn rooms and rules. It's funny when the whole team is killed off in classic Left 4 Dead style - perhaps three people are down and the last remaining guy is racing for the boat before a Charger runs him off the jetty - but the novelty of losing 10 minutes' progress is wearing off.

It wears particularly thin in a couple of areas - most notably the escalator-heavy mall section of Dead Center, and the planks-in-the-water bits of Swamp Fever - when Valve's famous ability to move you intuitively through the world falls a bit short and you end up getting spun around and lost. It won't be a problem when you learn your way through, but wasn't the point that you weren't supposed to have to?

Then again it feels a bit silly moaning about something that's otherwise so excellent, and you're never more than a few feet away from another joke, or gadget, or smart little gimmick that restores the smile to your face. The new characters, for example, like southerner Ellis and his comedy anecdotes, always cut short by the sweary but avuncular Coach, who also has the best situational dialogue: "S***, I need to heal my ass!" "Re-goddamn-loading!" Or the 7/11 store, Save 4 Less.

Or the new adrenaline shot, which temporarily speeds up your actions. Or the defibrillator, which can bring a dead team-mate back to life but occupies a med-pack slot for whoever carries it. Or the "uncommon common" infected - riot cops who only go down when shot in the back, or clowns whose noses you can honk. Or the Achievements, half of which must have been invented to fit the jokey labels, like "Septic Tank". Or the writing on the safe-room walls. Or the grenade launcher. Or the incendiary bullets. Or the Midnight Riders.