Single-player games like Ostranauts
Below are 16 single-player Steam games similar to Ostranauts, ranked by player overlap. Every pick carries Steam's Single-player category, so multiplayer-only titles or always-online games don't sneak in. imho.run pulls the category data from Steam directly — Single-player here matches what the store labels.
Want the full alternatives list (paid + free + Steam Deck + cheaper picks)? See the parent games like Ostranauts page.
Ranked picks
- 1
Hardspace: Shipbreaker
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Simulation with Ostranauts.
Equipped with cutting-edge salvaging tech, carve & slice spaceships to recover valuable materials. Upgrade your gear to take on more lucrative contracts and pay your billion credits debt to LYNX Corp!
- 2
Evochron Mercenary
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
The life of an independent mercenary is rarely without excitement. Your spacecraft awaits and your adventure begins in the Sapphire star system.
- 3
Stardeus
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
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.
- 4
NEO Scavenger
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and RPG with Ostranauts.
NEO Scavenger is a game where you must survive in the wasteland long enough to figure out who you are. Each turn, you must decide where to go, how to scavenge for supplies, and how to deal with anything and anyone you encounter.
- 5
ΔV: Rings of Saturn
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
A physics-based mining sim, set in the thickest debris field in Sol. Every action has a reaction, lasers are invisible without a medium, and your thrust is a potent weapon. Find trade, adapt your equipment to your playstyle, hire a crew to help. Unravel the mysteries of the rings, or just get rich.
- 6
Gaia Beyond
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
Gaia Beyond is a handcrafted 2D Action-RPG, an exploration mix built around the core features fighting, mining and trading. Your decisions are footprints within a vast non-linear solar system. Forge alliances among numerous factions and develop relations with hundreds of NPCs.
- 7
X4: Foundations
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Simulation with Ostranauts.
Your journey to building a vast space empire begins behind the controls of a single ship. Explore, trade, fight, and build as you rise to command fleets, stations, and entire economies in a living, fully simulated universe that reacts to every decision.
- 8
No Man's Sky
Single-player alternative to Ostranauts — playable solo, no multiplayer required.
No Man's Sky is a game about exploration and survival in an infinite procedurally generated universe.
- 9
RimWorld
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
A sci-fi colony sim driven by an intelligent AI storyteller. Generates stories by simulating psychology, ecology, gunplay, melee combat, climate, biomes, diplomacy, interpersonal relationships, art, medicine, trade, and more.
- 10
Project Zomboid
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
Project Zomboid is the ultimate in zombie survival. Alone or in MP: you loot, build, craft, fight, farm and fish in a struggle to survive. A hardcore RPG skillset, a vast map, massively customisable sandbox and a cute tutorial raccoon await the unwary. So how will you die? All it takes is a bite..
- 11
Stationeers
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
Stationeers puts you in control of the construction and management of a space station to run by yourself or online with your friends. Complex atmospheric, electrical, manufacturing, agriculture, and gravitational systems require your thought and management at all times!
- 12
Kenshi
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
A free-roaming squad based RPG. Focusing on open-ended sandbox gameplay features rather than a linear story. Be a trader, a thief, a rebel, a warlord, an adventurer, a farmer, a slave, or just food for the cannibals. Train your men up from puny victims to master warriors.
- 13
Barotrauma
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
Barotrauma is a 2D co-op submarine simulator – in space, with survival horror and RPG elements. Steer your submarine, complete missions, fight monsters, fix leaks, operate machinery, man the guns and craft items, and stay alert: danger in Barotrauma doesn’t announce itself!
- 14
Empyrion - Galactic Survival
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
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!
- 15
Alien
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
Alien is a visual novel exclusively for adults! This story is about a guy who has been dreaming of having sex with an alien woman for a very long time. At some point, this dream comes true and the guy finally fucked an alien woman!
- 16
Dwarf Fortress
Single-player alternative to Ostranauts — playable solo, no multiplayer required. Shares Indie and Simulation with Ostranauts.
Build a fortress and try to help your dwarves survive against a deeply generated world. Keep your dwarves happy, grow their community and beware of digging too deeply. The deepest, most intricate simulation of a world that's ever been created.