Grand Theft Auto IV

The phone's an interesting tool in general. As well as initiating multiplayer - about which we learned more this week - it can be used to snap pictures, send text messages (you can restart failed missions this way), and get in contact with your acquaintances. As you meet new people - remember, Niko is new to Liberty City - the phonebook gradually fills up. Select one and you can socialise with them, going out to strip clubs or a meal, or going on the lash.

These activities are entertaining in their own way: pissed up with Roman at your side, you move around the streets drunkenly - Euphoria's NaturalMotion catching you with convincing procedural animations as you stumble - and driving is almost impossible, as the screen blurs and tilts and the car slips left and right despite your best efforts. More than a novelty though, building social bonds with key characters is rewarded with extras: free cab rides from Roman, or guns delivered on demand by Little Jacob. When the phone beeps - as it often does to announce calls and text messages - it's worth paying attention.

Inevitably, it also draws you into missions, which use the game's improved graphics, physics and controls to propose new scenarios: phoning a contact in a park and watching to see who answers, for instance. One that we and others have been shown involves chasing down a police informant, at the behest of a steroid-pumped loudmouth called Brucie. Chasing him down is a matter of following his car and smashing it up so he gets out, before gunning him down, but reducing it to a single sentence overlooks much of its charm: the neatly scripted and choreographed cut-scene that kicks it off, the near misses as you lean out of the window firing your pistol on the freeway, and - in our case at least - the mission-accomplished phone call to Brucie, interrupted rather comically by a pickup truck smashing into Niko and sending him tumbling down the embankment. It's a good thing the game auto-saves after missions.

Euphoria's role throughout - articulating those tumbles, inarticulating drunken behaviour - is influential, and enables a lot of incidental humour. Like PAIN on PS3, there's a guilty delight in throwing Niko's unbreakable - albeit killable - body around the pointed streets of Liberty City, and Rockstar knows this. Smash into a barrier fast enough and Niko will be hurled through the windscreen. Our favourite physics gag, though, is the simplest: walking up the steps outside a municipal building, and shoving a man backward so he tumbles down the stairs. Old-school GTA was crying out for new-school physics, of course, not least in the stunt jumps that are once again sprinkled subtly around the city.

As you'll have read, there's even pleasure to be had just cruising across and around Liberty City. Taxi rides can be taken in rather than skipped over, allowing you to watch them from cinematic camera angles by holding a particular button or just sit inside peering out, asking the driver to flick to a radio station you like. Taking a speedboat from the first island's southernmost shores, you can glide through the water - the range of colours, and its behaviour, is remarkable - staring at the skyscrapers, bridges and ships in the distance. It does things, like the papered foliage, park fountains, glass fragments, GPS route-finding that obeys the law, an entire fictional working Internet - that would be back-of-the-box material in other games, but they're so incidental that the people walking us through the game didn't even mention them.

But then that's always been what GTA did that nobody else really managed: impressing and entertaining you, even when you're not looking for it. In this regard, GTA IV is no exception, but in every other regard, it looks exceptional.