Games like The Willow Man
Games like The Willow Man include Darkwood, Five Nights at Freddy's: Into the Pit, A Plague Tale: Requiem, Stray, and SOMA. We matched them by the tags players give The Willow Man on Steam (Action, Horror, Exploration, Dark, and 2D): closest matches first, and among equally close ones the better-known games.

Darkwood
Shared: Horror · Action · Adventure

Five Nights at Freddy's: Into the Pit
Shared: Horror · 2D · Exploration

A Plague Tale: Requiem
Shared: Action · Adventure · Exploration

Stray
Shared: Adventure · Exploration · Atmospheric

SOMA
Shared: Horror · Dark · Atmospheric

The Forest
Shared: Horror · Adventure · Action

LIMBO
Shared: Dark · 2D · Atmospheric

Tiny Bunny
Shared: Horror · Dark · Atmospheric

Little Nightmares
Shared: Horror · Adventure · Atmospheric

The Coma 2: Vicious Sisters
Shared: Horror · Action · Adventure

Little Nightmares II
Shared: Horror · Adventure · Dark

ANIMAL WELL
Shared: Exploration · Horror · 2D

Mad Father
Shared: Horror · Exploration · 2D

Five Nights at Freddy's: Secret of the Mimic
Shared: Horror · Action · Adventure

Outlast
Shared: Horror · Atmospheric · Dark

Ori and the Will of the Wisps
Shared: Action · Adventure · Exploration

Hollow Knight
Shared: 2D · Exploration · Atmospheric

Hellblade: Senua's Sacrifice
Shared: Atmospheric · Dark · Horror

Sally Face - Episode One
Shared: Horror · Dark · Adventure

Tomb Raider Game of the Year
Shared: Action · Adventure · Exploration

INSIDE
Shared: Horror · Dark · Atmospheric

Rise of the Tomb Raider™
Shared: Action · Adventure · Exploration

Total Chaos
Shared: Action · Horror · Adventure

Bendy and the Dark Revival
Shared: Horror · Action · Adventure