The current big question on the internet regarding Prey 2 is this: why did they get rid of portals? The official line is because portals aren't related to the story Human Head Studios want to tell with their FPS sequel, but I suspect it might have something to do with the fact that there's currently a perfectly decent game about portals doing the rounds and nobody would want to have their work compared side-by-side with Valve's.

Prey's original ideas are the same, according to developer Human Head Studios, and those themes of abduction and alien environments are now manifested in new protagonist Killian Samuels and the alien planet of Exodus, the player assuming the role of a free-running bounty hunter in an open world environment clearly influenced by Blade Runner.

You know what? I'm excited by that. Maybe you're the kind of person who isn't, and you've spent the last few weeks lamenting the decision to switch out a Cherokee protagonist for yet another white American soldier. At the end of the day, I thought Prey was a slightly stodgy shooter that never managed to escape the age of its 11-year development cycle, and I can't imagine anybody lamenting the original when faced with the refreshingly bold ambition of the sequel.

The game starts with you picking up the pieces of the airplane that was hoovered up by baddies in front of Tommy's eyes in Prey 1 - Samuels was on that plane, and he awakens on an alien ship within the wreckage of the aircraft. There are no other humans to be seen, but streaks of blood guide you around the fuselage and into a few confrontations with some of the aliens from the original Prey. Your hands are cut to shreds and you've only got a crummy pistol, and eventually you get knocked to the floor and knocked out with the butt of an alien rifle.

We flick to a later section, about a third of the way through the game, set in the Central City Bowery, an area rife with muggings, drug trafficking, and gambling. Supposedly this is the perfect place for a bounty hunter to set up shop. Exodus is a funny planet in that it doesn't rotate around an axis, so one side of the surface is always facing the sun. Central City is somewhere in the middle of these hot and cold zones, though you'll apparently visit all areas of the planet in the finished game.

Samuels tracks and eliminates his targets with guns, gadgets, and parkour, with upgrades for the former two available from various merchants scattered around the world. To see how different Prey 2 is to its predecessor you need only to look at the screen: weapons are holstered by default, and HUD elements are minimal. The focus seems to be on interaction, rather than shooting first.

Successful pursuit seems to rely on crossing a mix of both horizontal and vertical space. In the demo I watched the Human Head Studios representative made it all look painless; there's a chance manoeuvring across potentially complicated geometry may be slightly more difficult to regular players who aren't actively developing the game, though the base mechanics seem geared to assist with successful traversal. Come to an edge, for instance, and Samuels will raise his hand in acknowledgement if he's able to make the leap, solving the potential problem of quickly gauging distance in 3D space via a nice little visual cue, without the need for an overbearing prompt.

Gadgets range from shoulder-mounted cannons and anti-grav grenades to a scanning device that highlights points of interest as well as enemy targets, one that is powerful enough to show an outline of characters through walls.

On your travels sub-quests will be generated procedurally, so as you turn a corner you might stumble into a group of thugs beating somebody up. You can ignore the incident or deal with it, or in true GTA-style just go haywire and murder everybody. Crime sprees incur the wrath of the doughnut-shaped security droids hovering around most areas, and the more destruction you cause the more heavy-handed their response.

The main quest is bigger and more rigid, and has you chasing around for a mafia boss called Dra'Gar. Unlike in sub-quests, the target has to be captured alive, and there's no convenient blip on the scanner to let you ascertain his location immediately. Instead you're conveniently directed to another criminal, Krux, who'll pop up various times throughout the game. In this instance he'll tell you Dra'Gar's location if you either bribe him or throw his bodyguard off the very high building he's perched against, with the latter being chosen in the demonstration.

Doing this causes Krux to declare that you owe him a favour, which means he'll hand out quests down the line. It's not made clear if this would have happened anyway. Krux's information is good, however, and when you stumble upon Dra'Gar you trigger a lengthy chase sequence across futuristic railways and rooftops.

Dra'Gar has plenty of reinforcements and is using a personal teleporter, which makes him particularly difficult to catch, but eventually the thing goes on the fritz and binds him to one position. Again, it's not made entirely clear if it's possible to actually catch Dra'Gar before he finishes his gauntlet. As a last resort he offers you more than the price on his head to let him go, but he gets teleported away to space prison and you immediately end up in a tussle with his robot-summoning brother before the screen fades to black.

Former protagonist Tommy Tawodi will make an important appearance to tie up some loose ends in the series narrative, but the real star of Prey 2 is Exodus itself. The alien city is a living, breathing world with multiple alien races walking the streets going about their day-to-day lives. Meanwhile you're pirouetting off jutting structures, with an athletic skillset inspired by Assassin's Creed and Mirror's Edge, to catch bounties foolish enough to attempt fleeing.

Prey 2 will be released in 2012 for Xbox 360, PS3 and PC.