It's a common misconception that crime doesn't pay, one perpetuated by our parents and teachers and a moralising media, but the truth is, it does pay. Quite well, actually, which is why our elders and leaders try so damn hard to conceal the fact, but you only need to look at 50 Cent or the guys at Enron to realise you can make a pretty tidy living from acting outside the law. But the flipside of a life of crime is that it only pays until you get arrested or shot repeatedly. Again, see 50 Cent or the former Enron executives.

This risk versus reward dynamic is what draws us to illegal acts, and it's why TV shows and books about crime are consumed voraciously by a curious public. It's also part of what helped Grand Theft Auto rocket to the top of the bestsellers list time and time again, and just like how CSI and Law & Order have 187 spinoffs and variants, it was inevitable that someone would try to muscle in on GTA's thematic turf. That game was Saint's Row, which busted the proverbial caps in the metaphoric ass of the Xbox 360 back in 2006.

Saint's Row was more heavily focused on gangs and gangsta life, with more gold than the US Treasury and more raps than your local deli, yet its over-the-top violence, characters and storyline made it something of a hit. Two years later, and only a scant six-odd months since Rockstar's latest GTA opus, Saint's Row 2 has jacked a car and ram-raided the Xbox 360 again. With tongue planted firmly in cheek and the felonious funnies turned up to 11, it promised to supersize the original, and it does exactly that.

The story kicks off a few years after the original game, which saw your character blown up by a boat-based bomb, temporarily ending your crime spree while you lie in a coma in the prison hospital. Horribly burned and broken, you'll be given the chance to hit a plastic surgeon as soon as you begin, allowing you to conveniently reinvent your appearance – and your gender! After that, a former member of the 3rd Street Saints, AKA your gang, gets himself stabbed so he can meet up with you in prison and the pair of you can Shawshank your way out of the big house and out into a brave new world.

The more things change, the more they stay the same, and Stillwater is a case study for that old proverb. All the gangs from the first game are long gone – you took them out, remember? – but the city itself is still very much how it was. There's new crews of crims causing chaos, of course, and the Ultor corporation has launched an urban renewal program that saw the slums of Saint's Row turned into a shiny happy Mecca for their employees and corporate HQ. This means you'll be travelling roughly the same mean streets as before, but facing a host of new enemies and challenges as you do it.

While your foes have changed, the fundamental gaming experience is very much an evolution of what Saint's Row provided. The main thrust of the story involves three arcs, each one focusing on one of your rival gangs. You seek to destroy these enemies and you will do so through a variety of missions, but before you can embark on any of these slaughter-filled sorties, you need to earn respect. The respect system is one of the things that Volition used to rise above being a simple GTA clone, compelling you to delve into the ancillary activities and diversions before letting you loose on the more structured missions.

The advantages of this are twofold; firstly it keeps you playing the game and becoming more experienced at it, and secondly it allows you to earn a number of rewards and bonuses to help make things easier. These range from prosaic perks like discounts at clothes shops, to absolutely essential goodies like unlimited weapon ammo and faster health regeneration. Ultimately, it serves as a handy way to alleviate some of the frustration games like this can generate by giving the player a substantial edge and putting the emphasis on just having fun.

And fun is clearly a word that graces a lot of internal memos and motivational posters at Volition, because that's what the game is. The activities are great; running drugs, abducting hookers for your own harems, throwing yourself in front of traffic to scam insurance companies, assassinations, races...all the great diversions from the original Saint's Row are present and accounted for. But they weren't enough for Volition, so the team has added some truly hilarious new activities, which include devaluing real-estate by hijacking a waste removal truck and hosing down buildings and people with poo, or starring in the hit reality TV show FUZZ, where you dress as a policeman and brutalise people for misdemeanour crimes.

The fact that completing some of these activities is mandatory if you want to progress through the missions won't even register, because they're so much fun you won't consider it a chore. Moreover, there's enough variety that even if you do find one sort of diversion displeasing, there's at least a dozen others you can go and play instead. You can literally lose hours of your life to these activities though, and as you progress through them the bonuses you can unlock will really make the missions a lot more fun as well.

The missions were a source of some complaint in the original Saint's Row, namely because some just weren't fun, while others were too repetitive, and overall because the lack of sensible mid-mission checkpoints meant that you would be constantly replaying long stretches of incidental gameplay, like actually driving to the mission and listening to the briefing dialogue. Volition's sequel answers all these complaints by ramping up the fun factor and adding intelligent checkpoints to the missions to keep you engaged and enjoying yourself. It's not flawless by any stretch – the missions do all still feel pretty similar and some of the checkpoints are still too widely paced – but on the whole Saint's Row 2 is a solid update to the original framework.

And really, that's what Saint's Row 2 is: a solid update of an already enjoyable game. Very little has changed at a fundamental level, but virtually everything wrong with the original has been tinkered with or changed to make for a better experience. Targeting enemies is easier for one, replicating the zoomed-in but still third-person effect that Gears of War and GTA4 use. It's also little things too, like traffic persisting longer in your vicinity, so the sports car that just drove by will still be there when you pull a u-turn to persuade its driver to let you borrow it. And now when you get vehicles you own delivered, you'll have the option of automatically repairing them for a couple of hundred bucks so they arrive all shiny and new. It's all about making the game less of a chore and more fun! Of course that doesn't extend to the game's artificial intelligence which is incredibly stupid most of the time, getting stuck on doors and objects or just standing still while you shoot at it. This can be hugely frustrating, and even the new things the A.I. can do (like a homie jacking a car to follow you if your ride is full) don't make up for it.

This policy of logical, incremental upgrades does extend to the visuals, which really aren't that much better than the original Saint's Row, but address some of the underlying issues. The character models are a bit more detailed, as is the city, and the sudden pop-up of objects and buildings as content is streamed from the disc is less pronounced than before. Still, the sequel lacks the visual fidelity of GTA4, and there's an awful lot of graphical glitches and bugs, as well as some screen tearing and texture issues. It lends Saint's Row 2 a "final-beta” feel rather than a polished, finished product, and for a game that was already delayed by several months, it could really have done with a few more of testing and polishing.

It isn't all bad though; the game looks great while you're driving around or shooting people, and the city feels a little more detailed too, like an older, grittier version of itself. The characters look a lot better too, thanks to a much more detailed character generation system, one that now allows you to pick a male or female protagonist as well as various ethnicities, body shapes and plenty of facial details. Saint's Row 2 takes the customisation even further though, allowing you to pick a style for gang, as well as choosing what vehicles they prowl around town in. Factor in a huge variety of clothing and accessories – even more than the original – and it's clear that Saint's Row 2 is meant to be a game about you, right down to your choice of style. Whether that style is a giant hot-dog suit or hooker-chic or anything in between is entirely up to you.

Saint's Row 2 is all about the character, yours and everybody else's. There's a fantastic ensemble in this sequel, including a few from the original game like Jonny Gat and Troy. The new gangs are just as diverse – Jamaicans and the Yakuza as well as a monster-truck loving biker gang – and it gives rise to some memorable characters in the game. Celebrity voice talent goes a long way here, with Daniel Dae Kim and Michael Rappaport reprising their roles, and newcomers to the series Eliza Dushku and Neil Patrick Harris doing a great job as a pair of stoners, among many others. The dialogue is rude, crude and a lot of fun, at once helping Saints Row 2 feel both real and utterly over-the-top.

Soundtrack is key in a game like this, and once again Saint's Row 2 comes out punching with a solid variety of genres represented, including the obligatory rap and hip hop through to classical music and techno. Each station could probably have done with another song or two to keep it fresh, but the mix of newish music and older stuff makes for a nice variety. Of course you can still buy tunes at in-game record stores, and compile your own radio station of cherry-picked favourites. Outside the car stereo things still sound good, with plenty of ambient sounds to bring the city to life. The canned pedestrian responses do tend to get repetitive, but just like the original, Saint's Row 2 tries to keep it fresh by having the citizens of Stillwater talk about how your actions have affected their lives, or what they think about a gang lieutenant being taken down.

A lot has been said about how close to the original Saint's Row 2 is in this review, so it's probably about time to mention one of the fantastic new features that has been added: co-op. In Saint's Row 2 a mate can join you at any time to play through the game, and it's not just for mini-games or diversions – you can essentially play through the entire story mode with a friend if you'd like. Unlike its contemporaries like Mercenaries 2 and Fable 2 whose co-op can be frustratingly limited and simple in its implementation, Saint's Row 2's is robust and full-featured, with no constraints to what you and your buddy can do. The entire city is your playground at all times, and better yet any money and respect your co-op cohort earns is his to take back with him to his own game. Not only that, if they finish a mission or unlock a bonus, that goes back with the too! It's an awesome system and despite some occasional lag – and even a few game crashes unfortunately – it's worth the price of admission just to have a friend riding shotgun while you're fleeing the scene of the crime, or to have some help getting past tougher missions.

Of course multiplayer returns as well, and what once seemed pretty spiffy in the original now feels a tad dated compared to GTA4's multiplayer mayhem. Deathmatch, CTF and racing are all there, as well as a mode called Strong Arm, which sees you battling it out and doing the singleplayer activities as part of a team trying to earn as much cash as possible. Online performance is fine, but whether it stays well populated with players once the likes of Gears of War 2 and Call of Duty 5 drop is another matter entirely. Still, there's a lot of fun to be had there, and there's enough unique touches to keep it fresh, like being able to throw up tags on walls in the middle of battle to unlock bonuses for your team.