RAM Pressure

A free tactical multiplayer game with a plot twist, largely copying the combat mechanics from X-COM. Here you will find interesting turn-based battles, futuristic locations, a wide variety of allied units and enemies, a variety of equipment and leveling options for controlled fighters, and a detailed plot. 

The game also attracts with procedurally generated maps, which constantly keep you in suspense and force you to come up with new tactical maneuvers. And although the project is free, be sure to read the reviews and check the system requirements before downloading.