We're not alone in the universe... in fact, it's getting kind of crowded here. In Universe at War: Earth Assault, the latest in a long run of PC real-time strategy titles ported to the Xbox 360, our planet is invaded by not one, not two, but three alien races intent on settling their ancient interstellar war once and for all. This diversity of factions and strategy is the game's greatest strength, but in the end, may overwhelm console players relatively new to the genre.

The first third of the rather hokey science fiction campaign is played from the perspective of the Novus, sentient machine beings fighting alongside human allies to repel the Hierarchy, an alien breed that specializes in strip mining other world for resources. Later, you switch sides and control the Hierarchy's armies before finally moving over to the long-dormant and mysterious Masari. Each faction is led by three hero units with special abilities, though some are frustratingly fragile and should be kept out of combat as much as possible (because their death fails the mission).

Strangely, it is only during the last third of the campaign that a complex, global, turn-based territory conquest mode comes into play, letting you choose which territory to attack in your next real-time battle and carry persistent armies from one fight to the next. Sticking it in the end of the campaign like this makes the entire thing feel tacked on and superfluous. Thankfully, the scenario game mode puts it to much greater effect as you conquer the globe without a storyline to get in your way.

For hardcore RTS fans, Universe at War's genius lies in its asymmetrical faction design. The three races are about as different as they can possibly be, and each does everything in their own unique way, from resource collection to unit building. Even StarCraft didn't go this far, and that's really saying something.