Games similar to X4: Foundations:

Cities: Skylines is a modern take on the classic city simulation genre. The game introduces new game play elements to realize the thrill and hardships of creating and maintaining a real city whilst expanding on some well-established tropes of the city building experience. From the makers of the Cities in Motion franchise, the game boasts a fully realized transport system. It also includes the ability to mod the game to suit your play style as a fine counter balance to the layered and challenging simulation. You're only limited by your imagination, so take control and reach for the sky!

Biomutant is an open-world, post-apocalyptic Kung-Fu fable RPG, with a unique martial arts styled combat system allowing you to mix melee, shooting and mutant ability action. A plague is ruining the land and the Tree-of-Life is bleeding death from its roots. The Tribes stand divided. Explore a world in turmoil and define its fate, will you be its savior or lead it to an even darker destiny?

Age of Wonders: Planetfall is the new strategy game from Triumph Studios, creators of the critically acclaimed Age of Wonders and Overlord series, bringing all the exciting tactical-turn based combat and in-depth 4X empire building of its predecessors to space in an all-new sci-fi setting. Emerge from the cosmic dark age of a fallen galactic empire to craft a new future for your people. Explore the planetary ruins and encounter other surviving factions that have each evolved in their own way, as you unravel the history of a shattered civilization. Fight, build, negotiate and technologically advance your way to utopia, in a deep single player campaign, on random maps and against friends in multiplayer.

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

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.

Iris.Fall is a puzzle adventure game featuring striking visuals and a spellbinding theme of "light and shadow".

In Imagine Earth, players must protect and nurture a fledgeling space colony while wrestling against the forces of corporate greed and climate change. Establish trade, research new technologies, form alliances and wage economic warfare in a real-time battle for galactic survival. Features: Boldly Go: Imagine Earth is a real-time planet simulation and a build up strategy game. Your job as a space colony manager is to explore distant planets, build up profitable colonies, and trade resources into space. Many ways to play: A multi-planet story campaign, ‘competition’ mode with five enemy factions, ‘free play mode with endless procedurally generated challenges, and a Planet Editor with custom building and terraforming. Hold the line: Use tower defence mechanics to protect your colony from invading aliens, marauding space pirates, and swarms of locusts. Hostile takeover: Form alliances with other colonies and intergalactic traders, or wage crafty economic warfare to secure total financial dominance for your planet. Carbon footprint: Earth has been destroyed by an ecological collapse - will your new home go the same way? Keep your worldwide emissions to a minimum, or else suffer rising sea levels, freak weather events, and more.

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

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.

StarMade is a 3D sandbox space shooter created by Robin "schema" Promesberger, founder of Schine. The game allows players to explore the vastness of space; building factories; creating ships, space stations and structures out of various block types. Both single-player worlds and multi-player servers are available players. StarMade is currently in Alpha, and is a free-to-play game.