Another virtue is the atmospheric quality of the graphics. Sony has perfectly captured London's gloom and strikingly portrays gangsters posed in front of postcard icons such as Big Ben.

Gangs of London is mentally stimulating too, if you believe the puff. Sony portrays the shoot-'em-up as a cerebral affair, highlighting the variety and intricacy of the approaches you can take. 'Story Mode', for example, is all about employing 'strategy and skill to stay one step ahead of the competition'.

One wonders, however, whether the average player will be drawn by the game's apparent chess-like attributes or the violence. Gangs of London has already come under fire in the British press for glorifying the latter.

The game seems especially questionable because the railway battle scenario revives memories of last July's terror attacks on the London underground and the shooting by police of the innocent Brazilian electrician Jean Charles de Menezes.

But the main reason to be repelled by the game is more direct. London already has a serious gun problem.

I know all about it because, between 1998 and 2003, I lived a minute's walk from 'Murder Mile': Upper and Lower Clapton roads in the north London borough of Hackney.

A fellow Middlesex University graduate who taught at a Clapton school told me that, in response to a caution, one student once told him: 'Sir, if you do that again, I'll get my dad to come round and shoot you.'

In one of the many actual Murder Mile shootings that made the news, shots punched fist-sized holes into the side of a BMW, striking both passenger and driver. The car ploughed into three pedestrians and crunched a Nissan Micra before settling against the side of a night bus.

Commenting in the Observer newspaper, Philip Ettienne, a former undercover officer with the Metropolitan Police who recorded his experiences of infiltrating Yardie gangs in his book, The Infiltrators, said: 'It has always been a terrible area. The official number of shooting incidents is high but the reality is higher - a huge number of gun-related incidents go completely unreported. If you look at the call-out records for the ARVs [armed response vehicles], you'll find they go to Hackney more than anywhere else.'

In fact, Mr Ettienne added, if the ARV cops were at a loose end, they would hang around in Hackney because, eventually, the call always came.

The question is why the call was inevitable. One explanation the media often gave was the influence of 'gangsta rap' videos, which were hard to escape - they played incessantly at local gyms and bars.

Anyone could see that local black youths were mimicking the likes of bad boy rapper Tupac Shakur. They had the swagger, the narcissistically narrowed eyelids and the air of ruthlessness expressed as violence in Tupac videos.

The last thing that young Londoners - or for that matter youthful gamers anywhere - need to see now is a game that, a la Tupac, depicts thuggery in a flattering light. Gangs of London makes violence seem as much fun as the circus.

In one still, a pistol-toting Yardie in a Tupac-style headscarf is captured hanging in mid-air, raised by a fiery explosion. He looks god-like rather than the high school druggie dropout that most gangsters are.

Sure, most players will resist the temptation to mimic the uplifted gunman by engaging in shoot-outs in Shoreditch and knife fights in Finchley. But

some are likely to imitate some aspects because it is not just MTV rappers that the young imitate.

Computer games rub off on them, too. For evidence, look no further than the current trial of a man charged with being in a US gang that played the ultra-violent Grand Theft Auto video game by day then robbed and killed by night.

Along with other 'Nut Case' gang members, Demarcus Ralls, 21, allegedly terrorised the city of Oakland near San Francisco from late 2002 until early 2003. The rub is that the gangsters reportedly told police that they added an extra edge to their GTA play by taking it from the virtual to the real world.

Only the woolliest 1960s liberal could fail to see that, if thugs themselves admit they are influenced by video games, then video games must be suspect.

Either way, Gangs of London, which is scheduled to be released later this year for the PlayStation Portable device, seems both potentially destructive and pointless - you just do not need organised crime in the palm of your hand, especially if it's already around you.

Would-be wisecracks about multiculturalism aside, the division of crime on ethnic lines makes the game even more unattractive. On top of all its other flaws, Gangs of London is racist.