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.

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

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.

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.

A retro-future sandbox RPG set in a frontier era galaxy with procedurally-generated elements. Create, explore, trade, and battle to stake your claim among the stars of a wild galaxy!

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.

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.

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.

Cleanse the system of pirates, destroy their bases and free the captives. On the asteroids, build a base, mining colonies, explore asteroids and extract resources needed for survival. Develop buildings, build defenses and turn the asteroid into a fortress.

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

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!

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.

RealmCraft is an immersive 3D sandbox VR adventure in a blocky world, blending creativity and survival. Explore a vast procedurally generated open world, mine resources, craft tools, and build anything. Fight hostile mobs, find treasures, and enjoy smooth, intuitive VR gameplay.

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!

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.

Voxelantis is a sandbox building and survival game set in a flat or spherical voxel world. Build anything out of your imagination, or adventure into uncharted territories to fight dangerous creatures. You can and deserve to have a small home planet of your own.

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!

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,

Build, host, and survive in a persistent multiplayer space sandbox set in the outer Sol system. Construct orbital habitats, manage fragile station systems, and keep your crew alive while expanding through zero-g, Saturn-ring danger, and player-built infrastructure.

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

Space Engineers 2 is a playable Early Access Alpha sandbox focused on engineering, exploration, and colonization in a fully destructible universe. Design and build ships, stations, and planetary bases while uncovering the story of Miro and Ivan Sokol. Help shape the future of the Almagest system.

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.

Start and evolve a colony of Luminids, little creatures with personalities and needs of their own. Shape the land and watch them gather, build, and grow across forests, mountains, deserts, and frozen lands. Plan from above then step into first person to explore the world you built together.

A survival engineering game where you build life support habitats, mine resources, and automate production chains on a radiation heavy planet. No rescue. No support. Just engineering.

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?

Build an automated factory on a true-scale Mars streamed from real NASA terrain. Mine, smelt and belt resources, run trains between outposts, master chemistry, and grow from a lone lander into a planet-spanning industry while the real Martian weather does its worst.

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!

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.