Widelands
Widelands is a free, open source real-time strategy game
...Still, it is easy to get started through playable tutorials. In Widelands, you are the regent of a small clan. You start out with nothing but your headquarters, where all your resources are stored. In the course of the game, you will build an ever growing settlement. Every member of your clan will do his or her part to produce more resources - wood, food, iron, gold and more - to further this growth. The economic network is complex and different in the five tribes (Barbarians, Empire, Atlanteans, Frisians and Amazons). As you are not alone in the world, you will meet other clans sooner or later. ...