Haegemonia (US: Hegemonia) by Digital Reality is another real-time space strategy game with empire building as backbone. Really good too although a bit long to get into. Do Sins and Haegemonia have much in common? Has it even given Stardock some ideas and inspiration? (I heard its expansion The Solon Heritage did not come out in the US - a pity if true since it really improved and perfected an already impressive space strategy game.)