Games like Spoids
Games like Spoids include X-Morph: Defense, Sanctum 2, Defense Grid: The Awakening, Orcs Must Die! 2, and Infested Planet. We matched them by the tags players give Spoids on Steam (Strategy, Indie, Action, Tower Defense, and Old School): closest matches first, and among equally close ones the better-known games.

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

Sanctum 2
Shared: Strategy · Tower Defense · Action

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

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

Infested Planet
Shared: Strategy · Action · Tower Defense

Taur
Shared: Strategy · Tower Defense · Action

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

Space Run
Shared: Strategy · Tower Defense · Indie

Sanctum
Shared: Strategy · Tower Defense · Action

Anomaly Warzone Earth
Shared: Strategy · Indie · Action

Rock 'N' Roll Defense
Shared: Strategy · Tower Defense · Action

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

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

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

DG2: Defense Grid 2
Shared: Strategy · Tower Defense · Action

Rock of Ages
Shared: Strategy · Indie · Tower Defense

Thronefall
Shared: Strategy · Tower Defense · Action

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

Orcs Must Die! 3
Shared: Strategy · Tower Defense · Action

Kingdom Rush - Tower Defense
Shared: Strategy · Tower Defense · Action

Natural Selection 2
Shared: Strategy · Action · Indie

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

Rock of Ages 2: Bigger & Boulder™
Shared: Strategy · Action · Indie

Kingdom Rush 5: Alliance TD
Shared: Strategy · Tower Defense · Indie