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.
FlightGear - The FlightGear flight simulator project is an open-source, multi-platform, cooperative flight simulator development project. It also simulates space flight in Earth's orbit. It's flight dynamics engine (JSBSim) is used in a 2015 NASA benchmark.
ANNO - ANNO is a city-building and economic simulation video game series, with real-time strategy elements.
Microsoft Flight Simulator X - Microsoft Flight Simulator X is an exciting Open World, Realistic, Single and Multiplayer Flight Simulation developed by ACES Game Studio and published by Microsoft Game Studios.
Tropico - Tropico is an Addictive, Strategy, Construction and Management, City Building, Sandbox and Single-player Simulation developed by PopTop Software.
X-Plane - The world's most advanced flight simulator just got an upgrade. Download the free demo today for Windows, macOS, & Linux.