"The free edition of StarCraft 2"
StarCraft is a real-time strategy game that shows three different species fighting to conquer the universe: the Terran, the Zerg and the Protoss.
This special version is more complete than a Demo as you can play the first four missions, two competitions and you can modify the Terran race to make it in your image and likeness.
In this startup version you won't have access to the Zergs armies or the Protoss people but considering it's a kind of special version of the Demo, it's not bad at all. With what it offers you you have fun for a while. You only need to have your account in Battle.net and download this game to start enjoying it.