Games like Starpoint Gemini 2
Games like Starpoint Gemini 2 include Starfield, Elite Dangerous, X4: Foundations, Rebel Galaxy, and Starpoint Gemini Warlords. We matched them by the tags players give Starpoint Gemini 2 on Steam (Space, Simulation, RPG, Open World, and Sci-fi): closest matches first, and among equally close ones the better-known games.

Starfield
Shared: Space · Open World · RPG

Elite Dangerous
Shared: Space · Open World · Space Sim

X4: Foundations
Shared: Space · Simulation · Open World

Rebel Galaxy
Shared: Space · Open World · RPG

Starpoint Gemini Warlords
Shared: Space · RPG · Open World

Kerbal Space Program
Shared: Space · Simulation · Space Sim

Endless Sky
Shared: Space · Open World · Simulation

X Rebirth
Shared: Space · Simulation · Sci-fi

Cyberpunk 2077
Shared: Open World · RPG · Singleplayer

Fallout: New Vegas
Shared: RPG · Open World · Singleplayer

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

EVE Online
Shared: Open World · Space · Space Sim

Between the Stars
Shared: Space · RPG · Simulation

Mount & Blade II: Bannerlord
Shared: RPG · Open World · Simulation

STAR WARS™: Squadrons
Shared: Space · Simulation · Sci-fi

STAR WARS Jedi: Survivor™
Shared: Open World · Singleplayer · Action

Space Engineers
Shared: Space · Simulation · Open World

SpaceEngine
Shared: Open World · Space · Sci-fi

Dyson Sphere Program
Shared: Space · Simulation · Open World

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

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

SPORE™ Galactic Adventures
Shared: Simulation · Space · Open World

Starpoint Gemini 3
Shared: Space · Simulation · RPG

Avorion
Shared: Space · Space Sim · Open World