OpenRCT2 - Game engine recreation of RollerCoaster Tycoon 2 adding new features.
ANNO - ANNO is a city-building and economic simulation video game series, with real-time strategy elements.
Parkitect - Build the theme park of your dreams, and keep it running!
Stronghold - Stronghold Crusader is a RTS game from the series from Stronghold.
Planet Coaster - Planet Coaster is an Adventure-based, Management, Strategy, Sandbox, Building, Single and Multiplayer Simulation by Frontier Developments.
The Settlers Online - The Settlers is a free web browser based strategy game along with a gameplay that drops anywhere between Age of Empires and the online strategy style.