Games like Castle Guardian
Games like Castle Guardian include Kingdom Rush - Tower Defense, FOR HONOR™, Orcs Must Die!, Kingdom Rush Origins - Tower Defense, and Orcs Must Die! 3. We matched them by the tags players give Castle Guardian on Steam (Tower Defense, Action, Casual, Tactical, and Medieval): closest matches first, and among equally close ones the better-known games.

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

FOR HONOR™
Shared: Action · Medieval · Third Person

Orcs Must Die!
Shared: Tower Defense · Action · Third Person

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

Orcs Must Die! 3
Shared: Tower Defense · Action · Third-Person Shooter

Thronefall
Shared: Tower Defense · Action · Medieval

Orcs Must Die! 2
Shared: Tower Defense · Action · Third Person

Bloons TD 6
Shared: Tower Defense · Casual · Strategy

Mount & Blade II: Bannerlord
Shared: Medieval · Action · Strategy

Chivalry 2
Shared: Medieval · Action · Hack and Slash

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

Warhammer 40,000: Space Marine 2
Shared: Action · Third-Person Shooter · Third Person

Middle-earth: Shadow of War
Shared: Action · Fantasy · Third Person

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

GemCraft - Chasing Shadows
Shared: Tower Defense · Action · Tactical

Hitman: Absolution
Shared: Action · Tactical · Third-Person Shooter

Chivalry: Medieval Warfare
Shared: Action · Medieval · Third Person

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

Crimson Desert Enhanced
Shared: Action · Medieval · Fantasy

Caster
Shared: Action · Casual · Third-Person Shooter

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

Bloons TD 5
Shared: Tower Defense · Action · Casual

God of War
Shared: Action · Hack and Slash · Third Person

Orcs Must Die! Deathtrap
Shared: Tower Defense · Action · Third-Person Shooter