It must be said that an army of two is rather on the small side, although history has recorded some more compact forces than this. Such as Bjork, who claimed she was an army all on her own in the song "Army of Me." Although clearly no-one in their right mind would sign up for Bjork's army anyway, on account of the fact that she's completely bonkers and the uniforms would probably consist of giant swan suits.

Anyhow, back on track: Army of Two is a third-person co-operative shooter in which the pair of starring soldiers are so mega-hard (or mega-stupid) that they don't need any backup. The duo are actually mercenaries, taking on missions to earn cash and purchase new weapons or upgrades. And bling. Yes, if you've ever wanted to own a gold-plated AK-47, now's your chance.

Army of Two is designed from the ground up to be a co-op experience, played over Xbox Live or split-screen on the same console. However, it is possible to play alone, as the part of the second grunt can be taken by the computer AI, or PAI (Partner AI) as the game calls it.

Interestingly, the core concept for the co-op mechanics is borrowed from the world of MMORPGs - it's known as aggro. Whoever's firing more at the enemy draws their fire and glows red to show that he has their attention (or aggro). The other player is free to sneak around, semi-invisible, and get into advantageous positions in order to take them out with swift, targeted blasts.

Thus you really do have to work together and balance who has the aggro. If one player is nearly dead, the other can always take the heat off him by going nuts and letting fly with multiple rounds, while the injured party sits quietly behind cover and rests up. There are plenty of other situations where co-operative action is necessary, such as boosting each other up a wall, or having one player drive a vehicle while the other mans the guns.

When playing in single player mode, the PAI works pretty effectively and does a good job of covering you, and following simple orders ("stay put" or "advance") dispensed with a press of the D-pad. The controls are intuitive on the whole, and there are some neat touches like being able to hit the yellow button to slide along the ground into cover.

But while the co-op elements are smartly designed, the campaign itself falls a little short. The level design is disappointingly linear, and the strait-jacketed feel isn't helped by scripted set pieces such as when you go "back to back." This happens when you're surrounded by enemies, and time slow downs Matrix-style while you both stand back to back, mowing down everything in sight. It's good fun, yes, but it feels very artificial.

The plot and dialogue are also rather weak and clichéd, and the campaign itself is over fairly quickly. Still, EA has to be applauded for its co-op innovations in the shooter genre here, and Army of Two is undeniably a good blast, particularly when you have a friend along for the ride. No matter how good the computer PAI is, it can't replace the banter between two mates trying to take on the world.

As a true co-operative game, Army of Two succeeds in bringing some welcome originality to the shooter genre. Even though the core campaign is rather short and unimaginative, it's a game that's definitely worth experiencing. Especially when you've got a friend to play with, in split-screen or online mode.