Games like Toon Siege
Games like Toon Siege include Thronefall, Rogue Tower, Kingdom Rush 6: Genesis TD, Kingdom Rush - Tower Defense, and Bee Island. We matched them by the tags players give Toon Siege on Steam (Action RTS, Tower Defense, Arcade, 3D, and Isometric): closest matches first, and among equally close ones the better-known games.

Thronefall
Shared: Tower Defense · Action RTS · Action

Rogue Tower
Shared: Tower Defense · 3D · Casual

Kingdom Rush 6: Genesis TD
Shared: Tower Defense · Action RTS · Action

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

Bee Island
Shared: Tower Defense · Action RTS · 3D

Kingdom Two Crowns
Shared: Tower Defense · Minimalist · Controller

Age of Darkness: Final Stand
Shared: Action RTS · Tower Defense · 3D

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

Wolcen: Lords of Mayhem
Shared: Isometric · Adventure · Action

Kingdom Rush Origins - Tower Defense
Shared: Tower Defense · Casual · Cartoony

Ninja Kiwi Archive
Shared: Arcade · Tower Defense · Casual

Kingdom Rush 5: Alliance TD
Shared: Tower Defense · Cartoony · Adventure

Bomb Rush Cyberfunk
Shared: Adventure · Action · 3D

Deathtrap
Shared: Tower Defense · Action · Isometric

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

Street Fighter™ 6
Shared: Arcade · Action · Adventure

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

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

Kingdom Rush Frontiers - Tower Defense
Shared: Tower Defense · Adventure · Casual

Kingdom Rush Vengeance - Tower Defense
Shared: Tower Defense · Adventure · Action

Rogue Legacy 2
Shared: Arcade · Action · Adventure

ATLYSS
Shared: Adventure · 3D · Action

Orbt XL
Shared: Arcade · Controller · Action

Once Upon A KATAMARI
Shared: 3D · Adventure · Action