Games like Universal Combat CE
Games like Universal Combat CE include Elite Dangerous, Kerbal Space Program, X4: Foundations, Avorion, and Space Engineers. We matched them by the tags players give Universal Combat CE on Steam (Space, Sci-fi, Simulation, Strategy, and Action): closest matches first, and among equally close ones the better-known games.

Elite Dangerous
Shared: Space · Sci-fi · Space Sim

Kerbal Space Program
Shared: Space · Simulation · Sandbox

X4: Foundations
Shared: Space · Simulation · Sci-fi

Avorion
Shared: Space · Sandbox · Space Sim

Space Engineers
Shared: Space · Simulation · Sandbox

Stellaris
Shared: Space · Sci-fi · Strategy

Dyson Sphere Program
Shared: Space · Simulation · Sci-fi

No Man's Sky
Shared: Space · Sci-fi · Open World

X Rebirth
Shared: Space · Simulation · Sci-fi

Empyrion - Galactic Survival
Shared: Space · Simulation · Building

Hardspace: Shipbreaker
Shared: Space · Sci-fi · Simulation

Cosmoteer: Starship Architect & Commander
Shared: Sci-fi · Space · Strategy

SPORE™ Galactic Adventures
Shared: Space · Simulation · Action

Kerbal Space Program 2
Shared: Space · Sandbox · Simulation

SPORE™
Shared: Simulation · Space · Sandbox

SpaceEngine
Shared: Sci-fi · Space · Sandbox

X3: Terran Conflict
Shared: Space · Simulation · Sci-fi

Reassembly
Shared: Space · Strategy · Action

Starbase
Shared: Simulation · Space · Sci-fi

Between the Stars
Shared: Space · Simulation · Action

FTL: Faster Than Light
Shared: Space · Sci-fi · Strategy

EVE Online
Shared: Space · Space Sim · Simulation

Space Engineers 2
Shared: Space · Sci-fi · Simulation

Starpoint Gemini Warlords
Shared: Space · Strategy · Simulation