Rising Lands: Die Herrschaft der Clans - German title
Gameplay is similar to most real-time strategy games. You collect three different resources (food, stones and metal) and must utilize these to build new buildings, create armies, increase population and research new technologies.
One interesting twist is that in the single-player campaign, your actions in one mission are reflected in the next mission, so if you've made peace with another tribe, you will still be at peace in the next mission. All your research is also carried over between missions.