Parent game
In Kerbal Space Program, take charge of the space program for the alien race known as the Kerbals. You have access to an array of parts to assemble fully-functional spacecraft that flies (or doesn’t) based on realistic aerodynamic and orbital physics. Launch your Kerbal crew into orbit and beyond (while keeping them alive) to explore moons and planets in the Kerbol solar system, constructing bases and space stations to expand the reach of your expedition.
DLCs
Reach new heights in the critically acclaimed space simulation game Kerbal Space Program with the History and Parts Pack. Experience a variety of new content with pre-made missions inspired by humankind's most daring historical events, new parts to experiment with from the historic Space Race, and fresh suits to enhance the style of your Kerbals. Also included are new launch sites, with the Mun launch site not currently on PC!
Could be interesting
Sol 0 is a real time strategy game where you establish the first Martian colony. From the first human footprints on Martian soil to a thriving and self-sustaining colony, Sol 0 imagines a near future using technology that could be available within the next few decades. Make use of minerals and resources across the Martian surface to expand from the first exploratory rover to an independent frontier.
We take the colony sim genre into the near future, onto a lush planet where humans are making their first foothold. Characters and alien wildlife are brought to life through a rigorous simulation and the game plays out as a tug-of-war between humans and nature on a planet full of opportunities and dangers. Understanding the alien environment is crucial - discovered resources and crafting options enable you to adapt when food gets scarce, equipment breaks and alien animals attack.
Dude Simulator is an open world sandbox game. This is a life simulator. The main objective is to enjoy what you are doing.
Force of Nature is an indie open world sandbox game with fighting, crafting, building and farming systems.
Guide a group of space settlers trying to establish an outpost on a remote planet. Grow food, collect energy, mine resources, manufacture bots, and build a fully self-sufficient colony.
Rise of Industry is a strategic tycoon game that puts you in the shoes of an early 20th-century industrialist. Build and manage your growing empire in a living, breathing, and procedurally generated world that is constantly evolving and adapting to your playstyle.
The Earthlings have joined the interstellar club. The galaxy will never be the same. The year is 2086 and Earth has detected an alien distress call originating from the surface of Triton. In response, Star Control is formed with you as The Captain of Earth's first prototype starship.
A brand-new spaceship sandbox MMO set in an alternate New Eden, the sci-fi universe of Eve Online.
Academia : School Simulator is a management game that lets you design, construct, and manage the high school of your dreams! As the school Principal, watch your students as they get bullied, find love, flunk exams, and basically just try to get through the roller-coaster ride that is high school. Will you offer the best teachers and facilities or cheap out and build giant classrooms with a 1:100 student to teacher ratio? It's all up to you!
Two small classics from Clarus Victoria published in 2013, Stone Age and Bronze Age, are now available on Steam! Manage an ancient tribe in the African Savannah, build the first city in the Fertile Crescent, guide your people across prehistory and lead them to Victory!