Games like The Tomorrow War
Games like The Tomorrow War include Elite Dangerous, X Rebirth, EVE Online, Deliver Us The Moon, and SPORE™ Galactic Adventures. We matched them by the tags players give The Tomorrow War on Steam (Simulation, Action, Adventure, Space, and Sci-fi): closest matches first, and among equally close ones the better-known games.

Elite Dangerous
Shared: Space · Simulation · Space Sim

X Rebirth
Shared: Simulation · Action · Space

EVE Online
Shared: Adventure · Space Sim · Simulation

Deliver Us The Moon
Shared: Adventure · Action · Space

SPORE™ Galactic Adventures
Shared: Simulation · Action · Adventure

Rebel Galaxy
Shared: Space · Sci-fi · Adventure

Kerbal Space Program
Shared: Simulation · Space · Space Sim

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

Endless Sky
Shared: Space · Simulation · Sci-fi

X4: Foundations
Shared: Simulation · Space · Space Sim

Between the Stars
Shared: Action · Simulation · Space

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

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

Kinetic Void
Shared: Simulation · Space · Action

Space Rangers HD: A War Apart
Shared: Space · Simulation · Adventure

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

Starship EVO
Shared: Action · Simulation · Space

3030 Deathwar Redux - A Space Odyssey
Shared: Adventure · Action · Simulation

Starpoint Gemini 2
Shared: Simulation · Space · Sci-fi

House of the Dying Sun
Shared: Simulation · Action · Space

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

Warhammer 40,000: Space Marine 2
Shared: Action · Adventure · Sci-fi

LEGO® Star Wars™: The Skywalker Saga
Shared: Adventure · Space · Action

Trailmakers
Shared: Action · Space · Adventure