Games like Spirits' Forest
Games like Spirits' Forest include Kingdom Rush - Tower Defense, Potion Craft: Alchemist Simulator, A Dance of Fire and Ice, Melvor Idle, and Kingdom Rush Origins - Tower Defense. We matched them by the tags players give Spirits' Forest on Steam (Casual, Shoot 'Em Up, 2D, Fantasy, and Medieval): closest matches first, and among equally close ones the better-known games.

Kingdom Rush - Tower Defense
Shared: 2D · Casual · Singleplayer

Potion Craft: Alchemist Simulator
Shared: Singleplayer · Medieval · 2D

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

Melvor Idle
Shared: Casual · 2D · Singleplayer

Kingdom Rush Origins - Tower Defense
Shared: 2D · Casual · Singleplayer

Zup! S
Shared: Casual · 2D · Indie

Vampire Survivors
Shared: 2D · Casual · Indie

Game Dev Tycoon
Shared: Casual · Indie · 2D

Kingdom Rush Frontiers - Tower Defense
Shared: 2D · Fantasy · Singleplayer

Circle Empires
Shared: Casual · Fantasy · Indie

Plants vs. Zombies GOTY Edition
Shared: Casual · Singleplayer · 2D

Cyberhunt
Shared: Casual · Shoot 'Em Up · Indie

Kingdom Rush 5: Alliance TD
Shared: 2D · Singleplayer · Fantasy

The Adventure of NAYU
Shared: Casual · 2D · Fantasy

Timberman
Shared: Casual · 2D · Indie

Planes, Bullets and Vodka
Shared: Casual · Shoot 'Em Up · 2D

Cat Goes Fishing
Shared: 2D · Casual · Indie

DETOUR
Shared: Casual · Shoot 'Em Up · Indie

SAMOLIOTIK
Shared: Casual · Shoot 'Em Up · Indie

Reus
Shared: Casual · Indie · Singleplayer

BEEP
Shared: 2D · Indie · Singleplayer

Reigns
Shared: Medieval · Indie · Singleplayer

Touhou Tenkuushou ~ Hidden Star in Four Seasons.
Shared: Shoot 'Em Up · Singleplayer · Indie