Games like TechGuardian: Territory Defense
Games like TechGuardian: Territory Defense include Dyson Sphere Program, Creeper World 3: Arc Eternal, Mindustry, Taur, and Creeper World 4. We matched them by the tags players give TechGuardian: Territory Defense on Steam (Strategy, Indie, Tower Defense, RTS, and Sci-fi): closest matches first, and among equally close ones the better-known games.

Dyson Sphere Program
Shared: Simulation · Sci-fi · Resource Management

Creeper World 3: Arc Eternal
Shared: Strategy · Tower Defense · Indie

Mindustry
Shared: Tower Defense · Strategy · RTS

Taur
Shared: Strategy · Tower Defense · Indie

Creeper World 4
Shared: Tower Defense · Strategy · RTS

Planetary Annihilation: TITANS
Shared: Strategy · RTS · Sci-fi

Outpost: Infinity Siege
Shared: Tower Defense · 3D · Resource Management

Anno 2070™
Shared: Strategy · RTS · Simulation

STAR WARS™ Empire at War - Gold Pack
Shared: Strategy · RTS · Sci-fi

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

Starship Troopers: Terran Command
Shared: Strategy · RTS · Sci-fi

The King is Watching
Shared: Tower Defense · RTS · Strategy

Anno 2205™
Shared: Strategy · Simulation · Sci-fi

Cliff Empire
Shared: Strategy · Simulation · Sci-fi

They Are Billions
Shared: Strategy · RTS · Tower Defense

Oxygen Not Included
Shared: Resource Management · Base Building · Strategy

Defense Grid: The Awakening
Shared: Strategy · Tower Defense · Indie

Warpips
Shared: Strategy · Tower Defense · RTS

DG2: Defense Grid 2
Shared: Strategy · Tower Defense · Sci-fi

Tower Dominion
Shared: Strategy · Tower Defense · RTS

MarZ: Tactical Base Defense
Shared: Strategy · Tower Defense · RTS

Spacebase DF-9
Shared: Strategy · Simulation · Indie

Particle Fleet: Emergence
Shared: Strategy · Indie · RTS

Age of Darkness: Final Stand
Shared: Tower Defense · Strategy · RTS