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.

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

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 cities and factories in an infinite Hex World. Explore more tiles. Balance your city's production and consumption, attract more citizens of different classes, research new technologies and build more factories and cities.

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.

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?

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!

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.

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.

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.

An open world survival game set in space.

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.

Red Planet: Survive is a first person survival game for Microsoft Windows. Surviving in the harsh conditions of the Red Planet will be hard, but if you are strong enough, you will succeed. Find the best way to survive, but be careful, since each wrong step will ensure your demise. The environment is your main enemy.

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.

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!

Interstellar Rift is an open world starship simulator with an emphasis on ship construction and multi-player interaction. Survive in a hostile galaxy with your own custom designed and constructed starship. Invite other players to join your crew or fight them across the galaxy!

Massively multiplayer sandbox adventure with PvE, PvP, resource mining, crafting, progression, building and community.

A sandbox survival game, set on life-sized voxel planets with realistic physics with the possibility to shape your own building blocks. From your custom made furniture, walls to vehicle parts. You shape the blocks which can then be used to build buildings, spacecraft and aircraft.

QANGA: Dive into a sci-fi adventure of exploration and resilience across the cosmos. Merge your mind with a state-of-the-art cyborg crafted by ICLab's Industry labs, and journey through this expansive universe!

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.

Cube Universe is a first-person voxel RPG. Visit many different, procedurally generated planets. Team up with your friends to fight against fierce enemies in dungeons. Do quests to save the world from the forces of evil - or throw it into chaos.

Build, arrive, and move into new regions and planets in the depths of space. Whether you will establish a colony and trade or train soldiers and fight, everything is in your hands.

Rise is a persistent science fiction sandbox strategy MMO set on Vieneo, an exomoon about 225 LY from Earth. Use ground, air, and space vehicles to explore this vast open world of 100 million square kilometers in size! You are helping establish a living, breathing world with virtually no boundaries!

Voidless is a sci-fi space survival sandbox set in the near future within a realistic scale solar system. In first or third person, players can explore planets and asteroids, collect resources, and craft items. As well as building bases and ships, all with physics based flight and combat.

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

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!

A deep starship colony sim. Build your starship, manage air, water, food, fuel, energy, temperature and psychology to keep your crew alive across vast distances. Closed-loop system in space. Mining, wiring, plumbing, in-ship factory, (alien?) radio signals & translation, diplomacy, combat, and more.

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

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.

Million on Mars delivers the most realistic Mars city-building MMO experience. Granted 40 acres of real Martian terrain, shop for rovers, energy systems, & factories to begin production on Mars. Leverage your skills and rovers, prepare your settlement for the arrival of the initial 20 Martians.

Voxellands is the ultimate sandbox voxel experience — design items, hand-paint mobs, construct vehicles, invent machinery, weave magic. Explore. Gather resources. Create your world. Use VR and AR to customise your game!

Base One is a space base builder game where you take control of a network of space stations and its crew's tasks and wellbeing. Maintain your resources and defenses as you navigate the wide array of dangers ahead of you!

Explore space and build on other worlds in Star Rangers! Star Rangers is a space exploration and construction game that allows players to build habitats and spacecraft, acquire gear and explore the solar system.

2d space combat like no other. From the perspective of a single crew member, explore the fully destructible interior of any ship in a massive living world. Engage in space combat with no hitpoints where you know your enemy is dead when you see them fall out of their ship into the cold dark of space.

A procedural co-op space sandbox where players can build their own space ships out of dynamically scalable blocks. Fight epic space battles, explore, mine, trade, wage wars and build your own empire to save your galaxy from being torn apart by an unknown enemy.