Empyrion - Empyrion is a 3D open world, space survival adventure in which you can fly across space and land on...
Dead Frontier - Dead Frontier is among the few zombie based video games that you can obtain in your web browser and for free.
Avorion - Explore, build, fight, trad and mine in a procedural co-op space sandbox.
Galaxy on Fire - Galaxy on Fire is a space combat and trading simulation.
StarMade - StarMade is a Minecraft inspired 3D space shooter.
EVE Online - Player-created empires, player-driven markets, and endless ways to embark on your personal sci-fi adventure.