Games like Tower ships
Games like Tower ships include Defense Grid: The Awakening, X-Morph: Defense, Sanctum 2, Infested Planet, and Dungeon of the ENDLESS™. We matched them by the tags players give Tower ships on Steam (Indie, Tower Defense, Aliens, Sci-fi, and Strategy): closest matches first, and among equally close ones the better-known games.

Defense Grid: The Awakening
Shared: Tower Defense · Indie · Sci-fi

X-Morph: Defense
Shared: Tower Defense · Indie · Strategy

Sanctum 2
Shared: Tower Defense · Strategy · Indie

Infested Planet
Shared: Tower Defense · Indie · Strategy

Dungeon of the ENDLESS™
Shared: Tower Defense · Indie · Strategy

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

Anomaly Warzone Earth
Shared: Indie · Tower Defense · Strategy

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

Space Run
Shared: Tower Defense · Indie · Strategy

Revenge of the Titans
Shared: Tower Defense · Indie · Strategy

Taur
Shared: Tower Defense · Indie · Strategy

Buggos
Shared: Strategy · Aliens · Tower Defense

Natural Selection 2
Shared: Strategy · Sci-fi · Indie

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

Sanctum
Shared: Tower Defense · Indie · Strategy

Plants vs. Zombies GOTY Edition
Shared: Tower Defense · Strategy · Indie

Orcs Must Die! 2
Shared: Tower Defense · Indie · Strategy

XCOM: Enemy Unknown
Shared: Sci-fi · Strategy · Aliens

Buggos 2
Shared: Strategy · Aliens · Tower Defense

Legion TD 2 - Multiplayer Tower Defense
Shared: Tower Defense · Strategy · Indie

Bloons TD 6
Shared: Tower Defense · Strategy

GemCraft - Chasing Shadows
Shared: Tower Defense · Indie · Strategy

Space Run Galaxy
Shared: Indie · Tower Defense · Strategy

Orcs Must Die!
Shared: Tower Defense · Indie · Strategy