Games like Princess Defender Episode 1
Games like Princess Defender Episode 1 include Kingdom Rush - Tower Defense, Kingdom Rush Frontiers - Tower Defense, Kingdom Rush 5: Alliance TD, Plants vs. Zombies GOTY Edition, and Bloons TD 6. We matched them by the tags players give Princess Defender Episode 1 on Steam (Strategy, Tower Defense, Female Protagonist, 2D, and 2D Platformer): closest matches first, and among equally close ones the better-known games.

Kingdom Rush - Tower Defense
Shared: Strategy · Tower Defense · 2D

Kingdom Rush Frontiers - Tower Defense
Shared: Strategy · Tower Defense · 2D

Kingdom Rush 5: Alliance TD
Shared: Strategy · Tower Defense · 2D

Plants vs. Zombies GOTY Edition
Shared: Tower Defense · Strategy · 2D

Bloons TD 6
Shared: Strategy · Tower Defense · Singleplayer

Kingdom Rush Vengeance - Tower Defense
Shared: Strategy · Tower Defense · 2D

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

Kingdom Rush Origins - Tower Defense
Shared: Strategy · Tower Defense · 2D

Kingdom Rush 6: Genesis TD
Shared: Strategy · Tower Defense · 2D

Dungeon Warfare
Shared: Strategy · Tower Defense · 2D

Bloons TD 5
Shared: Strategy · Tower Defense · 2D

Celeste
Shared: Female Protagonist · 2D Platformer · Indie

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

Kingdom Two Crowns
Shared: Tower Defense · Strategy · Singleplayer

Relic Guardian - Tower Defense
Shared: Strategy · Tower Defense · 2D

Trine Enchanted Edition
Shared: 2D Platformer · Fantasy · Colorful

Hollow Knight: Silksong
Shared: 2D · Indie · Female Protagonist

Thronefall
Shared: Strategy · Tower Defense · Colorful

Totally Accurate Battle Simulator
Shared: Strategy · Singleplayer · Indie

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

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

A Dance of Fire and Ice
Shared: 2D · Indie · Singleplayer

Age of Defense
Shared: Strategy · Tower Defense · 2D

Warstone TD
Shared: Strategy · Tower Defense · Fantasy