Driver: San Francisco

Driver: San Francisco has scrapped on-foot sections because everybody else is doing them these days. Instead, going completely out-of-body is Driver's new Big Idea, for an age in which all driving games need Big Ideas, whether it's Split/Second's explosives and jaunty use of mid-word punctuation, Blur's social networking and power-ups, or Gran Turismo 5's absurdly long delays.

Reflections, the developer behind Driver, is calling its new mechanic Shift, and while it seems quietly deranged at first - a driving game in which you can hop into another car further down the road if you're getting left behind - it's a fascinating idea with some brilliant applications.

Reflections gets the justifications out of the way quickly. Tanner is a cop who believes an accident has left him with the power to detach his consciousness from his corporeal form and fling it out into the world where he can grab passing cars and commandeer them. In actual fact, an accident has left him in a coma, so I guess the joke is on him.

I repeatedly asked Reflections whether the 1971 Buick Riviera would feature: no clear answer. Still waiting to hear back on the '68 Ford Galaxy too.

Whatever's really happening, Shift is something you won't want to stop messing about with. One tap of a face button and you're out of your car, floating over the nearby stretch of road, from where you can highlight passing vehicles and see their stats, and then one more tap of the button warps you into them. If this were the 1950s, I'd have no problems declaring that little mechanic "nifty".

At the most superficial level, Shift means that chases have a real intensity to them, as Tanner's spirit hops from one car to the next to take down his foes. It quickly becomes clear that there's a rich strategic component too: why chase after somebody when you can steal a bus further up the road and ram it into them?

Later, missions even get rather puzzly. We're promised a flaming petrol tanker that you can cool off either by running over hydrants or by stealing a fire truck and sloshing it down with a side-on collision. (I'm pretty sure these strategies don't work in real life.) Back in 1999, Driver was one of the first sandbox games in terms of its world; now, a decade on, its missions are finally catching up.

I think there's a Denzel Washington film with a similar premise to this - but Denzel Washington doesn't have squashy seventies cop movie handling or 120 licensed cars.

Shift can be upgraded over time - you'll be able to increase its range over the course of single-player until you can take in almost all of San Francisco's 208 miles of roadway - and it's not free to use, either. Rather, it has to be earned by driving in a cool way: catching air, drifting, heading into oncoming traffic. Anybody who's owned a new Toyota in the past few years shouldn't have a problem.

Also, think about this: Shift opens Driver up in terms of its storytelling as well as its mechanics, as when Tanner's spirit hops into a new car the audience gets a sense of the lives of its owners. Reflections is promising hundreds of bespoke characters, all with their own little stories, and it will be using picture-in-picture to help the plot unfold without breaking up the game's flow.

If all of this sounds potentially rather distracting, players will always see Tanner as Tanner, even when he's hopped into someone else's body. It's a nice steal from Quantum Leap, and the developer is hoping it will be enough to remind you that you're still a cop who thinks he's on a desperate mission even as he eases an ice cream bus out into heavy traffic.

Creating a feeling of coherency isn't the only challenge for the team: Shift has to be seamless when it works - an instantaneous pan out from Tanner's car to the wider environment. It is so far, and that's pretty amazing given the game's huge city filled with such densities of traffic, delivered at a rate that never drops below 60 frames per second.

On top of that the team has had to build AI that can leap in behind the player and take over abandoned cars at will. With all that going on, it's astonishing that Reflections has managed to give the cars such personality, too. More than most driving games, this is a series where the handling alone is a character, and it's fascinating as you Shift between vehicles to see just how different they feel, from the stodgy Dodge Neon to the fragile Zonda.

If it's hard to tell just how single-player is going to unfold at the moment, multiplayer is much easier to get a handle on. The finished game will have nine different modes - and a now-obligatory experience points system - but Reflections is only showing one for the time being: Trail Blazer.

Trail Blazer is theoretically very simple: stay within the neon light-trails of an AI-driven target car to earn points, with the first player to get to 100 winning. Shift, however, changes all that. Unlike with the main game, Shift power is currently unlimited in Trail Blazer, and with four players each battle for supremacy quickly becomes insane as you leap in and out of different cars, leapfrogging each other to stay in the scoring zone.

Pedestrians scarper in a pleasantly hectic fashion.

The AI car weaves about a bit - possibly to make it more challenging but possibly because my dad is driving - and the game does a beautiful job of balancing the all-out chaos as you fight to get to the front, with a sweet note of pure precision as you seek to then stick tightly within the light trails and stay there.

Played on a stretch of downtown San Francisco (I could tell it was downtown because I was charged eight dollars for a watermelon juice) Trail Blazer feels nothing like a normal driving game. Actually, its lineage is rather hard to untangle: there's a hint of Mario Kart's battle modes in there, certainly, but a little of the frenetic brinksmanship of Mashed - gone but definitely not forgotten - and the treasure-sifting element of something like Monster Hunter as you Shift and then roam around looking for something special to steal. You almost always find something special too. Hints: Deloreans and the new Fiat 500s.

Pretty soon after getting to grips with it, Driver's out-of-body weirdness settles down, and you start to enjoy a racing game that you can play a little like God might - and it turns out that God really doesn't like taking corners. He prefers, instead, to hop from one car on a straight to another car on the next straight, and such impromptu tactics give Reflections' latest a unique rhythm, a rhythm that's both strategic and hilariously cruel.

Damage modelling is fully implemented: astonishing considering all the licensed cars knocking around.

It's going to be weird, after long sessions, to return to games where you can't do this, and there's a special kind of pleasure that comes from executing a barge manoeuvre so perfectly that you can then watch to see a rival Shift into a speeding Maserati just as it piles through a wall.

Something has to suffer, of course, and due to the huge world and massive numbers of cars, the textures can be a little rough. It's earlyish days, however, and the lighting, more importantly, is already beautiful, with god rays lancing through the skyscrapers as you drive around America's most iconic car-chase city.