I can't quite shake the suspicion that MindJack might be slyly taking the piss. Take a look at this video, and you'll see what I mean. The content is clearly sincere - or at least as sincere as sci-fi hokum gets - but the gravelly narrator appears to be winding us up. At one point he tells us about an enemy who wears "thick armour that acts as a protective suit" - as if armour ever does anything else. Later on he introduces the Titan, a bioengineered enemy that's more or less a silverback gorilla with mechanical bits bolted onto it.

Now, let's think about this for a second. A quick spot of Wiki-journalism tells us that there are around 104,620 gorillas in the wild in 2010 (that's the rough ape-total of the Western Lowland, Eastern Lowland and Mountain classifications). The Western gorilla population has declined by 50 per cent over the past three decades, and Mindjack is set in the year 2031, so it's unlikely there will be more than 70,000 gorillas (or thereabouts) available at the time of the game's events. Moreover, Mr Narrator specified that Titans are made out of silverback gorillas, and silverback status is only gained by apes who attain a dominant position in a group. Even if one in seven apes successfully climbs their local social hierarchy (which seems unlikely), MindJack's villains will only have 10,000 animals on the entire planet to use for their nefarious schemes.

All I'm saying is... it sounds a bit impractical.

Okay fine, so now I'm the one taking the piss. The fact of the matter is that MindJack has ROBOT GORILLAS in it, and that alone is enough for me to take interest. It's also got mechanised bonobos, too; I was planning to fire off some stats about declining monkey populations, but I should probably get on with talking about the game itself.

Technological trans-simians aside, MindJack boasts two attention-grabbing features: a gameplay mechanic that allows you to possess the bodies of your injured foes, and an open-ended structure that lets other players "hack" into your game, fighting alongside you or taking direct control of your enemies. I've covered both of these devices in detail in my previous preview, which was based upon a largely hands-off E3 showcase, but it wasn't until the end of last year that I really got to give them a proper test run. I've now played through two stages from the game's second chapter, following heroes Jim Corbijn and Rebecca Weiss as they battle their way through an airport packed with armed security forces.

The first thing to note about MindJack is that it's pretty challenging - or at least it is if you're playing with three people who've worked on the game. Granted, I may not be placing enough emphasis on my own incompetence here, but the presence of human opposition certainly seemed to make things harder than what you'd normally expect from a third-person shooter. Even with a human ally backing me up (we were playing 2vs2), I found myself under constant pressure, largely due to the near-constant need to hop back and forth between bodies.

MindJack may resemble a standard third-person shooter, with a control scheme that does nothing to defy the established setup, but in play there's an almost RTS-like need to control space and resources (in this case, NPCs you can manipulate). Stages break down into self-contained, arena-like battles, with Corbijn and his pert sidekick taking on multiple waves of enemy troops. Hostile players who've entered your game initially appear as floating red digital clouds, until they assume control of an available body - which in their case could be anyone aside from the two protagonists. Corbijn and Rebecca, on the other hand, are only able to assume control of foes who've been gunned into near-death submission; if you go too far and actually murder them, you won't be able to use their carcass. Provided you manage to dish out just the right amount of damage, you can either reanimate them to serve as an unwilling assistant, or assume control of them directly.

The heroes are also able to possess or recruit any innocent civilians who may have wandered into the area. It doesn't seem particularly heroic when Corbijn takes over an air hostess and then uses her as a meat shield, but no doubt he'd just justify it as being "necessary collateral damage". Civilians will occasionally be found carrying a surprisingly powerful weapon, however, so don't feel too bad about snatching away their self control. Besides, it's funny to try and beat people up as a killer British Airways attendant.

While human bodies make up the bulk of your potential hosts and allies, other options are also available. Sadly neither the Gorilla (sorry, Titan) nor the bonobos were available in my demo, but I did at least get some time with a few security droids. The flying ones obviously have the advantage of manoeuvrability, but personally I found more use for their ground-based cousins: they're small enough to avoid attention, and speedy enough to launch surprise hit-and-run raids on threats behind cover.

In truth, I suspect that these aggressive tactics probably weren't such a smart move on my part. For all its bells and whistles, MindJack is still very much a cover-to-cover shooter, and dashing into the fray will usually result in death for you or your host body. The seriousness of this occurrence is somewhat dependent on who else is playing, and what the current situation is. If your recently-mutilated corpse belonged to an enemy or a civilian, you'll simply need to assume control of someone else - you can do this manually, in floaty ghost fashion, or by using a shoulder button to skip to the nearest available vessel. If, on the other hand, it's Corbijn or Rebecca who's gone face down in a pool of blood, they'll need to be revived - and this is clearly only possible if you've got a human ally to help you out.

MindJack certainly succeeds in offering a rather original risk/reward dynamic. If you don't push forward and acquire new bodies to occupy, the enemy will overrun you - but by abandoning Corbijn's shell you automatically increase your chances of befalling disaster. It's an engaging mechanic, but while the basic shoot-and-hide controls are undeniably familiar, they lack the precision and fidelity we've come to expect from the genre. As I've said, the game's nature forces the player to act quickly and intelligently while under strain. It's a situation that demands reliable controller response, but too often I felt that it was the wooliness of the underlying design, rather than my own human error, that had led to my downfall.

With the game due for release in roughly two weeks, we'll soon know how serious a setback these issues actually are. Japanese developer feelplus has clearly tried to offer a new slant on an over-worked formula, but if they've slipped up on the basics, it'll be that much harder for the innovation to shine through. All the same, I'm not judging the game just yet - not till I've had a proper go on that gorilla, at any rate.

MindJack is due for release on Xbox 360 and PS3 on January 21.