CM-SS13

Space Station 13 (ss13) is a multiplayer role-playing game. Originally created by one person named Exadv1, development has been continued by members of the fan base.

Gene Rain is a next-gen 3D third person shooter game. The story is set in a futuristic world, with a linear narrative structure, and uses shocking visual effects to present a brand new world for the players ' enjoyment.

Immortal: Unchained is an action role-playing game and third-person shooter with a high difficulty level and a focus on firearm combat, though basic melee weapons such as swords, axes, and clubs are also available. Enemies have critical weak points, typically the head and a glowing spot on their backs, that can be targeted for extra damage. The game is set in an alternate universe whose backstory draws on Norse mythology, spanning Nine Realms tied to a central artifact called the Monolith.

Star Control: Origins is a science fiction action-adventure game that combines planetary exploration, diplomacy with alien races, and one-on-one ship-to-ship space battles. Players captain a starship, sending a lander to survey planets, gather resources, and examine artifacts, then spending those resources on new technologies, weapons, upgrades, and ships from other races. The top-down Fleet Battles pit two vessels against each other and can be played against the AI or in multiplayer. It is considered part of the Star Control series but takes place in a separate universe from the original games.

A brand-new spaceship sandbox MMO set in an alternate New Eden, the sci-fi universe of Eve Online.

Rebel Galaxy Outlaw is an open-world space combat adventure game, spread across the nearly 40 systems of the Dodge Sector. Play as a mercenary, a trader, a pirate, or whatever mix of the three you feel fits you best. With an engaging storyline and a full conversation system, you can follow the narrative, or ignore it and forge your own path at any time.

Force of Nature is an indie open world sandbox game with fighting, crafting, building and farming systems.

Breach & Clear brings deep tactical strategy simulation to PC, Mac and Linux! Build your Special Operations team, plan and execute advanced missions, and own every angle. Choose your real-world squad -- US Army Rangers, Germany's KSK, Canada’s JTF2, UK SAS, and more -- and take on a variety of foes with different skill-sets and abilities. Learn to approach, engage, and dominate your opponents through superior tactics and training.

Escape from Tarkov is a hardcore and realistic online first-person action RPG/Simulator with MMO features and story-driven walkthrough.

Citadel: Forged With Fire is a massive online sandbox RPG with elements of magic, spellcasting and inner-kingdom conflict. You have complete freedom to pursue your own destiny; hatch plots of trickery and deceit to ascend the ranks among allies and enemies, become an infamous hunter of other players, build massive and unique castles, tame mighty beasts to do your bidding, and visit uncharted territories to unravel their rich and intriguing history. The path to ultimate power and influence is yours to choose.

Dude Simulator is an open world sandbox game. This is a life simulator. The main objective is to enjoy what you are doing.