Game have added Galactic Civs into their 3 for 10 multibuys (online only) - a great deal if you like turn based strategies. As far as I know all other places selling this have it priced much higher (around £25-30). Here's something about the game (It's basically Civilization in a sci-fi setting.) :
In the year 2225, mankind’s thirst for domination has spread to the stars, where the battle for conquest rages on. Humans struggle for supremacy over the other Galactic powers, who have their own plans for the cosmos. Among these is the dreaded Drengin Empire, who will stop at nothing to wipe out humanity and its allies, though even they cannot imagine the horrors that exist in the furthest reaches of space… In Galactic Civilizations 2, you will use technology, diplomacy, colonization and war as your tools to build a far-reaching interstellar empire. You alone have the power to choose the path your people will take to ultimately become the rulers of the universe.