Games like Planet Strike
Games like Planet Strike include Kerbal Space Program, Universe Sandbox, Exo One, ScooterFlow, and SpaceEngine. We matched them by the tags players give Planet Strike on Steam (3D Platformer, Billiards, Space, Mars, and Physics): closest matches first, and among equally close ones the better-known games.

Kerbal Space Program
Shared: Space · Physics · Space Sim

Universe Sandbox
Shared: Space · Physics · Space Sim

Exo One
Shared: Space · 3D Platformer · Physics

ScooterFlow
Shared: 3D Platformer · Physics · Simulation

SpaceEngine
Shared: Space · Casual · Space Sim

Space Engineers
Shared: Space · Physics · Simulation

Hardspace: Shipbreaker
Shared: Space · Physics · Simulation

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

Kerbal Space Program 2
Shared: Space · Physics · Space Sim

Elite Dangerous
Shared: Space · Space Sim · Simulation

Totally Accurate Battle Simulator
Shared: Physics · Simulation · PvP

Universe Sandbox
Shared: Space · Physics · Simulation

Empyrion - Galactic Survival
Shared: Space · Simulation · Space Sim

Assetto Corsa
Shared: Simulation · Physics · Realistic

Garry's Mod
Shared: Physics · Casual · Simulation

Golf With Your Friends
Shared: Casual · Physics · Sports

Rooftops & Alleys: The Parkour Game
Shared: 3D Platformer · Simulation · 3D

Solar Expanse - Space Exploration Manager
Shared: Space · Physics · Simulation

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

Pool Nation
Shared: Billiards · Casual · Simulation

STAR WARS™: Squadrons
Shared: Space · PvP · Simulation

BMX Streets
Shared: Simulation · Physics · 3D

Drifter Star: Evolution
Shared: Space · Physics · Casual

V: Rings of Saturn
Shared: Space · Physics · Space Sim