Freeciv is an Open Source empire-building strategy game for Windows and Linux inspired by human civilization's history. There is also a portable version available.
FreeCol is a turn-based strategy game based on the old game Colonization, similar to Civilization. The objective of the game is to create an independent nation.
Mindustry is a tower-defense sandbox factory game. Build supply chains of conveyor belts to fuel your turrets, produce building materials, and defend your structures from waves of enemies.
StarCraft is a military science fiction media franchise set at the beginning of the 26th century, centering on a galactic struggle for dominance between four species.
Seven Kingdoms: Ancient Adversaries is a real-time strategy (RTS) game that enables players to compete against up to six other kingdoms allowing players to conquer opponents by defeating them in war (with troops or machines), capturing their buildings with spies, or offering opponents money for their kingdom.
0 A.D. is an open-source, historical Real-Time Strategy (RTS) game where you have to gather the resources you need to raise a military force and dominate your enemies.
Master of Tactics is a fast-moving, action-packed turn-based space strategy game. Strategize the colonization of new worlds while exploring the galaxy.
The Days After Christmas takes place a week after Christmas and you find yourself alone at the location of a Christmas house party but no one is there and you want your promised gift.
Fortify is a strategy game with a tower defense feel. Defend your castle from attacking monsters and siege weapons by using ranged and melee defenders, catapults, cannons, oil fields and more.
Deep Space Fire is a fun strategy game based on the Milton Bradley Battleship game. Build up your space fleet and wage war against the machine in ten separate campaigns.