Games like Rockhopper
Games like Rockhopper include No Man's Sky, Starfield, Elite Dangerous, FTL: Faster Than Light, and Wall World. We matched them by the tags players give Rockhopper on Steam (Space, Mining, Roguelite, Exploration, and Crafting): closest matches first, and among equally close ones the better-known games.

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

Starfield
Shared: Space · Exploration · Sci-fi

Elite Dangerous
Shared: Space · Exploration · Sci-fi

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

Wall World
Shared: Mining · Roguelite · Exploration

DAVE THE DIVER
Shared: Exploration · Adventure · Relaxing

Starbound
Shared: Space · Crafting · Adventure

EVE Online
Shared: Exploration · Space · Adventure

Outer Wilds
Shared: Space · Exploration · Adventure

Star Valor
Shared: Space · Exploration · Mining

EVERSPACE™
Shared: Space · Roguelite · Sci-fi

Heat Signature
Shared: Space · Sci-fi · Roguelite

Deliver Us The Moon
Shared: Space · Adventure · Sci-fi

Starcom: Nexus
Shared: Space · Exploration · Sci-fi

A Game About Digging A Hole
Shared: Mining · Exploration · Crafting

Rebel Galaxy
Shared: Space · Sci-fi · Adventure

Endless Sky
Shared: Space · Sci-fi · Adventure

Galactic Mining Corp
Shared: Mining · Roguelite · Space

STAR WARS Jedi: Survivor™
Shared: Adventure · Space · Sci-fi

Out There: Ω Edition
Shared: Space · Sci-fi · Exploration

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

Dome Keeper
Shared: Sci-fi · Space · Roguelike

Jump Space
Shared: Space · Roguelite · Sci-fi

SPORE™ Galactic Adventures
Shared: Space · Exploration · Adventure