The best Simulation Games alternative to Command & Conquer is CaesarIA, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to Command & Conquer and four of them are Simulation Games so hopefully you can find a suitable replacement. Other interesting Simulation Games alternatives to Command & Conquer are IL-2 Sturmovik, The Patrician and LandGrabbers.
CaesarIA is an open source remake of Caesar III game released by Impressions Games in 1998, it aims to expand the possibilities of the classical city-building simulators and to add new features showing the city life. Now the game work with Windows, Linux, Mac, Haiku and Android.
IL-2 Sturmovik is a series of World War II combat flight simulator video games originally created by the Russian video game developer Maddox Games under the brand name 1C:Maddox Games, following its association with 1C Company.
The Patrician is the title of a series of historical trading simulation computer games for the PC, Amiga and Atari ST published by Ascaron Entertainment. In the games, the player assumes the role of a merchant in any of several cities of the Hanseatic League, accumulating money...
LandGrabbers, recognized as the Best Casual Game of the Year at the 2011 Russian Game Developers Conference (KRI 2011)!
Cyprus
EU
Germany
Russia
Its not an RTS but an combat flight simulator.