Irrational Games stepped away from the BioShock franchise after the first title was released back in '07. BioShock was the spiritual successor to the System Shock games from the Nineties, and if you throw both of those games into the mix then you can argue that Irrational had been working on the Shock games for almost twenty years. It's fair to say that the studio was due for a new IP.

Now cut back to a few weeks ago. Project Icarus popped up online, immediately catching the interest of the blogging public. The teaser site briefly became a bit of a pleasure sock for forums and game sites. You'd spot comments sections swelling with gossip and nuggets of analysis, but in the end the game was just another BioShock title.

And you could feel that sense of disappointment. The consensus was that this was "BioShock in the air," "Airoshock", or even "SkyoSh*te" in some particularly disapproving quarters. The issue had little to do with the trailer that had been unveiled; it was more that as gamers we are jaded buggers, used to being continuously crapped on by the numerous series cash-ins that are secreted by the games industry.

And Irrational's lead designer Ken Levine tells us he had expected this.

"I think it's not surprising that people were sceptical, because I think in order to fulfil people's expectations you have to defy them to some degree. And how do you pitch or write that story about this game? It's not an easy story to write. Same with the original BioShock. When people wrote about BioShock it wasn't an easy story to write. What is it? Is it an FPS? Is it an RPG? Is it a horror game? Is it a survival horror? But getting back to that feeling of 'what the f**k?' was really important to us.

"It's like if you look at the Star Wars prequels. I think one of the challenges those films have was that it was like, 'Oh, you know all these guys from those movies? This is how they got there'. At the end of the day, this is not that interesting. It's fan service. 'Oh there's C-3PO!' That's not what's interesting to me. People asking all these meta-questions about how [Infinite] connects with the franchise is much more interesting a question than, 'Oh, C-3PO didn't originally have the golden armour on' because that's just fan service. It's not what we're looking to do."

In terms of the last two titles, BioShock: Infinite is set a good thirty or forty years prior to its sibling BioShocks. You're looking at a period somewhere in between the American Civil War and WWI when America was transitioning from a simple, small-town blot on the map to an industrial powerhouse. It's a period in history that had just recently introduced the telephone, the phonograph and basic automobiles, when twenty years prior Yanks were still kicking back in a horse and buggy and yelling to each other across the fence.

So the flying city that you've spotted in the trailer, Columbia, is an extension of that tech explosion. It's a government experiment that was first concocted as an example of American exceptionalism, to show what the States alone were able to conceive then construct. Columbia was designed to travel across the world but at some point after its launch it was revealed to be an armed battleship, built to impose American ideals on a worldwide scale. Like Rapture, Columbia started showing signs of ideological extremism, with ideas of racial purification and xenophobia cropping up around the ol' sky city.

Take a stroll down the streets of Columbia and the propaganda posters are unavoidable. "They'll take your wife," says one. "They'll take your job" says another. Columbia functions as a hyperbolised version of small town America, all full of quaint street corners, religious mentalists, and jingoistic ideals.

You play Booker DeWitt, a muscle guy hired to find a woman who has been locked inside of Columbia for reasons unknown. In standard BioShock tradition, she has powers. Enemies will gather around to attack the girl, Elizabeth, and she'll squint her eyes like she's trying to do multiplication, then suddenly knives and forks will burst from a nearby crate and explode out into the incoming baddies. And in another BioShock tradition there's a catch to using those powers, with Elizabeth crumbling to the floor with a nose bleed after her attacks. As DeWitt you have a grappling hook and powers reminiscent of those that went hand-in-hand with plasmids; along with Elizabeth you try to fight and escape from an enormous robot monster - one that houses a beating human heart.

"We like telling stories a certain way," Levine continues. "And because [what we did in BioShock] is not something that people have done a tonne of, there's a lot of room left to explore. We kind of felt like if we did a totally new IP and we did the same narrative techniques and the tool techniques, people would say, 'Why isn't this a BioShock game?'"

There's been a general sentiment surrounding the game that, "if it looks like a duck and it quacks like a duck then it's BioShock 1 all over again". And in terms of those gameplay and narrative techniques, Infinite is undoubtedly riffing off of the years of BioShock that have passed before - and perhaps even to the years of System Shock before them. It's another steampunk-styled environment with the same fighting mechanics that you saw back in 2007, but the changes are held a bit deeper inside. The philosophical and thematic tone is so drastically different from the broken down Randian water world of the last two games that it could have easily been developed into its own IP. BioShock Infinite looks a hell of a lot like a duck, but the game doesn't quack.

BioShock Infinite is due for release on Xbox 360, PS3 and PC in 2012.