Top similar games like Sigma World Online:

Dual Universe is a first-person Sci-Fi MMO built and driven by players, in a single persistent universe. You can build almost anything out of voxels, trade in a free economy, lead industries, travel through space, explore planets, or wage war in a fully editable sandbox universe. Subscription-based.

The ultimate space sandbox. Participate in epic fleet battles, form alliances, strive to dominate entire galaxies and harness the universe’s resources for your industrious empire or the destruction of others. Customise your experience, the universe is yours!

Factory management and sandbox base building in zero-g environment. Survive, expand and then dominate space industrial market. Build large scale resource processing plant completely from nothing.

Dig, Build, Explore! In this sandbox survival game, venture through a vast procedurally-generated infinite world. Mine resources, construct your homestead, craft and drive vehicles, delve into mining, cultivate, livestock, automated machinery, and uncover the truth behind the world.

Triton Survival is an open world survival game about exploration, construction, engineering, and fighting on planets. Embark on this interstellar adventure and conquer the galaxy. Are you ready?

Embark on a space voyage with your ragtag crew of civilians in search of a new home. Build spaceships tile by tile, create optimal gas conditions, manage the needs and moods of their crew, encounter other space-faring groups, and explore the universe in this spaceship colony simulation.

An open world survival and automation game. Engineer Alpha combines an infinite editable world, building and connecting of automated machinery, and RPG style player progression.

Build and manage space outposts on the Moon and Mars in this realistic simulation game. From the first step on the Moon to Mars colonization, launch rockets, take care of your astronauts and expand your base as you explore the cosmos. No grind, just pure management and exploration fun.

The ultimate space capital ship combat compendium is the evolution of hard core space combat sims. The only game of its kind currently in existence.

Starbase is a hybrid voxel/vertex-based space MMO with a fully destructible and infinitely expanding universe, with a focus on building and designing spaceships and stations, exploration, resource gathering, crafting, trading, and combat.

Medusa Frontier is a budget sci-fi survival game being developed with OpenGL & C++. Gameplay is currently limited to resource gathering and base building on a 1k terrain map.

An open world survival game set in space.

Shape your citizen, forge your destiny and sculpt your world in this epic voxel sandbox MMO built on endless possibility.

Spiritus Astrum is a persistent, open-world, multi-player, roleplaying sandbox. It features an infinite, procedurally generated universe which players are free to explore without restriction. Spiritus Astrum is more than a game, it is a world.

Remains - survival in outer space orbiting the planet. Explore the area. Find a way to restore oxygen. Create tools for your needs. Beware of the dangers of outer space. Build your shelter in orbit and try not to die!

Icaria is a robot colony builder where everything can be programmed. Build factories, design logistic networks, terraform the landscape, and explore an unknown alien world.

RealmCraft is the original Sandbox Game. Try to Survive & Use 100+ Types of Blocks to Build Your Unique Town

This is a voxel style sandbox game that focuses on survival. You can do anything inside and destroy any block. and cooperatively survive and fight with friends in a world. If you like playing Minecraft, this is a game you must not miss.

After a century in cryosleep you find yourself stranded amidst the ruins of mankind’s first interstellar colony. Explore derelict ships and stations and harvest raw resources in search of air, fuel and other equipment. Or loot and pillage what you need from other survivors. The choice is yours!

An exploration and building game inspired by games like "Minecraft", "LSD: Dream Emulator", and more.

Embark on a cozy open-world survival journey inspired by ancient China's heritage. Gather resources, cultivate crops, build your dream home, and defend it from marauders. Team up with friends to explore and uncover a world where adventure meets serenity.

Build the most efficient intergalactic factory in space simulation strategy game Dyson Sphere Program! Harness the power of stars, collect resources, plan and design production lines and develop your interstellar factory from a small space workshop to a galaxy-wide industrial empire.

A free-to-play MMORPG with crafting, building, landscaping, foraging, hunting, fishing, a dash of poetry, and open PvP combat,

The conquest of the Solar System has begun – prove yourself as a space colonist! Pilot the spaceship, choose the planet you wish to inhabit and build your new home. However, remember that there are no rules or laws in outer space. Don't underestimate the danger and stay vigilant – enemies are near!

No Man's Sky is a game about exploration and survival in an infinite procedurally generated universe.

Starfall Protocol is a Starship colony sim with RPG adventures in a galaxy with millions of explorable planets!🌌

Untethered is a space survival-sandbox set in our own cosmic backyard. Explore zero-gravity environments, build and operate realistic space stations, and fight to stay alive in the unforgiving realm of deep space.

Grab your jetpack and explore procedural asteroid fields, derelict spaceships and abandoned outposts. Build and automate your Space Rig to process scavenged trash. Craft, trade and fight your way home in this interstellar, open-world survival sandbox.

Build and explore in a true space sandbox survival adventure. Construct mighty capital vessels, sprawling planetary settlements, and vast space stations in your galactic journey to discover the mysteries of Empyrion!

Build your ship, defend against drone waves and explore hundreds of sectors filled with stations, asteroids and planets with lots of POIs. The ship systems can be controlled via consoles with several hundred buttons. Craft equipment and blocks, loot the POIs and disabled drones.

Planet Explorers is an open world sandbox adventure RPG game set on a distant planet. The game uses a new OpenCL calculated voxel system to allow players to change the terrain in any way, create new objects such as weapons, vehicles, objects, and do it anywhere.

Build ships from scrap and fly them in a gritty, realistic space sim. Venture solo or team up. Hunt for parts, haul vital resources, and keep your space agency afloat.

Stardeus is a deep colony sim set on a broken starship manned by drones and hibernating human survivors. As the AI, have your drones repair your ship, save your crew and travel the stars in this beautiful simulation.

As an engineer stranded in an alien star system, scavenge parts and build equipment to fight your way back home. Work with (or against) the laws of physics in MEANWHILE IN SECTOR 80 to turn trash into survival.

After a mysterious accident you are left are stranded, floating through space on a piece of a space station. Craft supplies and Hubs to expand what is now your home. But be warned space is a dangerous places where one mistake can mean certain death. Can you defy the odds and survive in space?

Guide a group of space settlers trying to establish a base on a remote planet. Grow food, collect energy, mine resources, survive disasters and build a self-sufficient colony in a harsh and unforgiving environment.