Rockstar Games, famed for the celebrated blockbuster series Grand Theft Auto, puts its gamers in a very different world with its stunningly paced, brilliantly written crimefighting thriller L.A. Noire.

And though some very obvious elements of the Rockstar MO remain, the rub is this - you're a good cop trying to read people's faces rather than a bad outlaw trying to blow them off. L.A. Noire, set in crime-ridden post-war 1947 Los Angeles, puts Rockstar's lovers of violent games into the flat shoes of Cole Phelps, a returning Silver Star-winning soldier who becomes a cop with more morals than was acceptable in those heady Hollywood days. Unlike GTA or Red Dead Redemption, the focus has moved from being a wide open-world gun fest to a more steered and focused storyline.

The environment is sandbox-huge, however, with everything in the central part of 1947 LA accurately modelled from roads and landmarks, to roach-infested apartments and cheesy billboards. But Phelps' wander through the city is dictated by breaking cases, and while there are loads of mini-missions for a bit of action-packed diversion, time is better spent combing crime scenes for clues and interviewing witnesses and suspects than stealthily tailing crooks or running down robbers. It's paced like a TV show rather than a noir film - with the investigations broken up by GTA-style car chases, gun fights and foot chases through the cityscape.

The heart of gameplay is MotionScan, a new multi-camera technology that accurately captures every little facial expression from hundreds of real actors - meaning no more jerky, wooden, badly-synced characters.

During Phelps' meteoric rise through the department from beat cop to homicide dick (and back, as the excellent James Ellroy-reminiscent story twists and turns) the key to his success is interviews and interrogations.

Once a crime scene has been checked for clues - some pivotal case-breakers, others as useless as a used bus ticket - and leads have been chased down, the truly innovative part of the game begins.

Every time you ask a question, it's vital to watch every expression from the suspect - a hard swallow, downward glance or weird twitch could give away that they're lying. Next, you're given three response options - truth, doubt or lie - which you have to choose. Get these wrong and your witness could refuse to talk to you, or you'll miss a pressure confession. This doesn't kill the game though - you don't ever totally miss a win, but mistakes you made could see Phelps getting knocked back to traffic duty.

An in-game intuition credit system - accumulated through success - can either reveal all clues at a crime scene, or narrow down the available response, can make it easier. But it's the thrill of making the early bust, picking the suspect reactions properly and soaking up the glory and grabbing the promotion.

Cole Phelps is acted by Mad Men ad exec Aaron Staton, who does a fantastic job, but the peripheral characters really make the story - hardened gangsters, alcoholic wannabe starlets, pervy casting couch producers and bolshie police captains - offering some of the best moments and most difficult interviews.

Rockstar has made a bold and risky move with L.A. Noire - taking the gamer from GTA carnage to moralistic war hero policeman with a dark secret. But there's no doubt it is one of the best written, acted, set and paced games out there, and this lengthy, innovative noir cop thriller is a must-play.

Stars: 5/5
Platforms: Xbox 360, PS3
Classification: R18