In the red corner, weighing in at over 1000lbs (minus the egg sack), the beast with acid for blood and a family of face huggers - Alien. And in the blue corner, weighing 280Ibs (if you can see him), the extra-terrestrial with more weaponry than Smith & Wesson and a penchant for headhunting - Predator. And in the middle, a bunch of gun-toting humans with little clue and even less hope - the Marines. Now that's a celebrity deathmatch we'd pay to see

But rather than being engaged in a standard beat-'em-up or FPS bullet-fest, this is the first RTS outing on Xbox - a point-and-click battle for domination where you can play through a seven-mission campaign as each of the species. There are 21 missions in total - not bad for the budget price of 20 quid.

Each race brings its own unique style of play to the party. The Aliens are all about strength in numbers and as such, their gameplay is based on population - the Queen being able to lay enough eggs and your face huggers able to find enough hosts to impregnate and transform into a growing army. Predators prefer quality not quantity, practising stealth attacks and high-tech kills due to their advanced weaponry and cloaking devices. Marines focus on ranged projectile attacks and strategic troop positioning - due to the inclusion of valuable yet fragile medics.

Reinforcements and upgrades are available for each species, with the economy largely based on kills. Predators clock up credits by taking heads, the Marines fix generators for cash and the Aliens infest as much as they can. It's a smart way of getting past the typical ‘mine or harvest' scenario. And as cash can provide you with new units (of which there are between eight and ten per species), it's important to stay on top of your game.

But there are problems. Visually it looks poor, with limited character detail and barren, mundane maps. There are issues with pathing and AI. Selecting a large number of units and directing them to a position will result in part of your group just ignoring your route and going a completely different way, often headfirst into an untimely demise - never good when trying to accumulate numbers for a big push.

Aliens Vs. Predator: Extinction offers a beginner's guide to the RTS genre. With no base building or real resource management issues you're not going to need a Grandmaster's forward-planning skills to achieve your goals. But with decent variation in gameplay styles and the attraction of playing a new genre on Xbox, there's enough here to keep both old fans and RTS newbies entertained - at least for the short term.

1. It's a strategy game... on Xbox!
2. Very different gameplay styles
3. Simple controls

1. A bit unsophisticated
2. Uninspired maps
3. No skirmish mode

Power
Glitch-free with no real slowdown - even when there's a full-scale battle happening.

Style
Drab maps and poor character detail, but three views allow you to get close up to the action.

Immersion
A RTS is a love or hate affair - get into it and time will pass on fast forward.

Lifespan
Twenty-one missions and three difficulty settings but only single-player and no skirmish mode.

Summary
By no means a classic but by no means a turkey, A much-needed shot in the arm for those that like to think before they fight.