Destroy All Humans! 2

There should be more anal probes in mobile games. It would've certainly given a whole new dimension to Paris Hilton Diamond Quest. But so far, just one game is flying the flag for up-the-bum alien experimentation: THQ's Destroy All Humans.

This is the game that turned the tables on the space-adventure tradition by letting you play an alien, gleefully running around killing earthlings (but not before having a look up their... Well, you get the picture).

Now it's got a sequel, which provides a refreshing antitode to samey old action-adventures by making the action turn-based. Characters have a set number of action points per turn, which are used to move, fire, throw grenades and heal themselves. It's a direct throwback to the heyday of board-based RPGs like Space Crusade and Heroquest, and it makes for a much more cerebral game, allowing you to plan your moves every turn and switch between characters at will.

Characters? Why yes. Although the central character of Destroy All Humans 2 is still a feisty Furon alien called Cryptosporidium, you can also take over enemies for short periods using mind control, which lets you move them around, unlock doors, and fire at their puzzled colleagues. Plus, early-ish in the game you get to rescue a squad of mercenaries and put three of them under 'long-term' mind control, as your team.

What this adds up to is a squad-based adventure, complete with cash to upgrade your team's weapons'n'armour.

The plot concerns your alien race, the Furons, having to quash human uppitiness on the colonised Earth. It involves a mission-based structure, with each mission having primary objectives (you HAVE to achieve them to progress) and secondary objectives (they're not essential, but do boost your score).

The result is an involved tactical adventure, bolstered by the different skills of your mercenaries – for example, there are medics, snipers and scouts. Although the objectives for each mission are pretty straightforward and linear, there's a pleasant amount of freedom about how you approach them, so you can opt for sneaky stealth or gung-ho blasting.

That said, the difficulty level does ping around a bit, in that there's a fair amount of opening doors to be confronted by two or three gun-toting enemies, invariably as you've just used up your last action points for that turn. Suffice to say, until you learn to be more cautious (or splash out on heavy armour to protect yourself), you'll be retrying levels frequently.

Without wanting to fence-sit, this'll be a selling point for some gamers, and annoying for others.

Destroy All Humans 2 isn't in the very upper tier of mobile games, and is unlikely to appeal to many gamers who've been weaned on real-time action adventures, rather than the more traditional turn-based mechanic used here. Nevertheless, it's a sparky game that provides a significant challenge, with enough original touches to make it worth a place on your phone – especially if you're a sci-fi fan.