Pioneer - Pioneer is a space adventure game set in the Milky Way galaxy at the turn of the 31st century.
X-COM - X-COM is a Science-Fiction, Turn-base Tactics, Strategy and Single-player video game series developed by Mythos Games and published by MicroPose.
X - It is a science fiction space trading and combat simulator series.
Xenonauts - Xenonauts attracts greatly on the sci-fi universe of the original X-COM to make a very familiar turn based tactical adventure.
EVE Online - Player-created empires, player-driven markets, and endless ways to embark on your personal sci-fi adventure.
Mount & Blade II: Bannerlord - Mount and Blade II: Bannerlord is an Action-Adventure, Hack and Slash, Single-player and Multiplayer video game developed and published by TaleWorlds Entertainment.