It's all very well creating an interactive sandbox world, full of compelling scenery and special effects that would make The Matrix look like a Benny Hill Christmas Special, but if there's nothing for you to do, what's the point?

Sure, we all loved Rockstar's Grand Theft Auto IV. The technical accomplishment was impressive, as the environmental detail of Liberty City simply hadn't been seen before on that scale. But once the story ran out, there wasn't really a whole lot to do.

This is the problem facing open-world titles today. Which is why 2K may have a challenge on their hands with Mafia II.

We joined the Australian 2K team in Auckland yesterday to check out a developer walk-through for this much anticipated mob sequel.

The original Mafia, released in 2002, was hugely successful on the PC platform, however the PS2 and Xbox versions were notorious for their lack of optimisation. This time around, Prague-based 2K Czech are developing Mafia II for PC, Xbox 360 and PS3, so the differences between the platforms should be minimal.

Shifting the story forward two decades has allowed Mafia II's artists to focus on America's post-war spending boom. Liberal quantities of skyscrapers, well-attired citizens and vehicles constructed out of left-over battleship steel can be seen within the fictional Empire Bay area, and the attention to detail inherent in almost every interaction you have with the environment is obvious. Again, as with GTA IV, you won't find loading screens between indoor and outdoor locations. What is definitely more apparent is the relationship between the two; standing in high-rise buildings looking out at the city doesn't appear to induce any frame drop, and events continue seamlessly with or without your interaction.

We were shown a mission entitled Room Service, the objective of which is to plant a rudimentary bomb in the same room as a conference attended by a rival mob family. The problem is, this conference is near the top of a skyscraper in the downtown city area, which naturally presents a number of logistical challenges to even the hardest of made men. After taking a short trip to the designated mission area, we managed to enter through the basement and convince some cleaners to loan us their uniforms. From here, we were able to make our way through the building to the conference room, and subtly attach a block of explosives to the underside of the central table.

Again, the attention to detail shown during this process makes it pretty obvious that 2K have sunk some serious time into research. I'm no expert on fifties fashion, or indeed fashion at all, but all the NPC's look incredibly convincing in their period attire, and even their language and gait is all reminiscent of a time when a man could alight a train, spark up an enormous Cuban cigar and look derisively upon anyone who dared complain.

The bomb arming mechanism is period accurate too - no fancy wireless detonators. No modified pagers or cellphones - just a long cable reaching out the window. One would assume the foremost criminal minds of the city might spot this, but then as they're having their conference in front of translucent glass in full view of the city, they're clearly not too worried about personal safety.

The next task is to get to the rooftop, and it's here we're given a choice. As the rooftop is currently occupied by gangsters, we can either charge in with guns blazing, or attempt to convince them to head downstairs. As this is a demo, it's pretty obvious that the gun option is the most applicable, so we're treated to a display of the cover mechanism and shooting gameplay. There's nothing too revolutionary about this, and we're informed by the developers that all typical 50's weapons will be available in the finished game; pistols, shotguns, and tommy guns appear to make up the staple choices we've seen so far.

After cleaning out the enemy, we negotiate our way down the side of the building on the window cleaning platform conveniently appropriated for this purpose. Upon reaching the same level as the conference room, we rig the bomb and hastily raise the platform to escape the blast. The result is suitably impressive - the blast ejects broken glass out on to the street and leaves a gaping hole in the side of the building. Unfortunately however, we didn't hit our target, as the mob boss running the meeting wasn't actually in the room when the device was detonated - this leads to a dash through the building to take out as many mobsters as possible, before confronting the boss in a car chase.

Unfortunately, we didn't get to see the final outcome of this mission, as 2K were keen to avoid giving away too much of the plot. What we have seen does indicate to us that Mafia II will be similarly weighted between missions, gunfights and driving as its predecessor, and it's really the length of these activities and the number of them that will decide its fate.

With one Mafia-themed title already failing to live up to expectations this year, we hope that 2K take the time to add the additional polish that is so necessary in sandbox titles to elevate them beyond mere GTA knock-offs. There's no shortage of inspiration with the history of the Mafia to draw on.