Games like Crystal TD
Games like Crystal TD include Thronefall, Age of Darkness: Final Stand, Artisan TD, Bloons TD 6, and Bee Island. We matched them by the tags players give Crystal TD on Steam (Strategy, Tower Defense, Action RTS, Real Time Tactics, and Incremental): closest matches first, and among equally close ones the better-known games.

Thronefall
Shared: Strategy · Tower Defense · Action RTS

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

Artisan TD
Shared: Strategy · Tower Defense · Real Time Tactics

Bloons TD 6
Shared: Strategy · Tower Defense · 3D

Bee Island
Shared: Strategy · Tower Defense · Action RTS

Broken Arrow
Shared: Strategy · Real Time Tactics · Action RTS

Creeper World 4
Shared: Tower Defense · Real Time Tactics · Strategy

DG2: Defense Grid 2
Shared: Strategy · Tower Defense · Real Time Tactics

Northend Tower Defense
Shared: Tower Defense · Strategy · Action RTS

Emberward
Shared: Tower Defense · Strategy · 3D

Bills Must Be Paid
Shared: Strategy · Incremental · Relaxing

Rogue Tower
Shared: Strategy · Tower Defense · 3D

ISLANDERS
Shared: Strategy · Building · Relaxing

Kingdom Rush Origins - Tower Defense
Shared: Strategy · Tower Defense · Building

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

Shadow Tactics: Blades of the Shogun
Shared: Strategy · Real Time Tactics · Tactical

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

Tiny Tactics
Shared: Strategy · Tower Defense · 3D

Outhold
Shared: Tower Defense · Strategy · Incremental

Element TD 2 - Tower Defense
Shared: Tower Defense · Real Time Tactics · Strategy

Kingdom Two Crowns
Shared: Tower Defense · Strategy · Building

Dungeon Defenders
Shared: Tower Defense · Strategy · Tactical

Sudden Strike 4
Shared: Strategy · Real Time Tactics · Action RTS

Warhammer Age of Sigmar: Realms of Ruin
Shared: Strategy · Action RTS · Real Time Tactics