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.

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.

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.

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.

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.

Stranded in deep space, you must survive against all odds. Scavenge from wreckage, process resources, and build your own space station - a refuge in the most hostile of environments.

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.

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, Explore, Fight. Build a ship of your imagination, explore the vast cosmos, and fight for your stake in the galaxy.

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.

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.

Survive and colonize Mars in a highly technical, open-world sandbox game. Build and upgrade your base, discover new regions, conduct mining operations, retrieve water, generate oxygen, grow crops, and fix broken parts.

Build your ship, manage your crew and explore the cosmos whilst trying your best to keep your crew alive and your ship fully functioning. This game utilises an events driven AI and simulated ship systems to ensure gameplay is kept challenging and every game you play has a different story to tell.

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.

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!

Spaceship building sandbox game. Build various spaceships from scratch and explore the cosmos. Fight different enemies and mine metals and materials to fix or expand your spaceship fleet.

In this survival sandbox, get ready for a big adventure - in a miniature universe of tiny planets! Construct & defend machines, design factories, fight bosses, and build a mini-empire across the mini-verse!

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.

Take command of your own colonial ship. Ensure the survival of your inhabitants and try to find a new habitable planet. This is the goal of the the Exodus H Space Commanders.

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.

Top Town is an upcoming life simulation game. Create a character and define your own goals and identity by choosing a profession and hobbies. Buy your dream house, visit stores and explore in a persistent and reactive world.

Elusive Verge is a third-person space exploration game with dash of base-building, combat and survival.

PlanetS is a space-themed open world game, allowing the player to explore the mysteries of the universe and various planets. First or third person camera, Craft system, flight simulation and online multiplayer.