Games like The Bookman
Games like The Bookman include Summer of '58, MiSide, Firewatch, Five Nights at Freddy's: Secret of the Mimic, and Fears to Fathom - Ironbark Lookout. We matched them by the tags players give The Bookman on Steam (3D, Horror, Walking Simulator, Atmospheric, and Thriller): closest matches first, and among equally close ones the better-known games.

Summer of '58
Shared: Horror · Atmospheric · Thriller

MiSide
Shared: Horror · 3D · Atmospheric

Firewatch
Shared: Atmospheric · Walking Simulator · Adventure

Five Nights at Freddy's: Secret of the Mimic
Shared: Horror · 3D · First-Person

Fears to Fathom - Ironbark Lookout
Shared: Horror · Atmospheric · Thriller

Five Nights at Freddy's: Security Breach
Shared: Horror · 3D · First-Person

The Cabin Factory
Shared: Horror · Walking Simulator · Atmospheric

Outlast
Shared: Horror · Atmospheric · First-Person

Resident Evil Requiem
Shared: Horror · Action · First-Person

The Forest
Shared: Horror · Adventure · First-Person

Dollmare
Shared: Horror · 3D · Simulation

Welcome to Kowloon
Shared: Horror · Atmospheric · Walking Simulator

Layers of Fear (2016)
Shared: Horror · Walking Simulator · Atmospheric

Zoochosis
Shared: 3D · Horror · Atmospheric

Garten of Banban
Shared: Horror · 3D · First-Person

Alan Wake
Shared: Horror · Thriller · Action

Backrooms: Escape Together
Shared: Horror · Atmospheric · First-Person

Scanner Sombre
Shared: Horror · Walking Simulator · Atmospheric

What Remains of Edith Finch
Shared: Walking Simulator · Atmospheric · First-Person

Who's at the door?
Shared: Horror · Walking Simulator · Simulation

Amnesia: A Machine For Pigs
Shared: Horror · Walking Simulator · Atmospheric

September 7th
Shared: Horror · Walking Simulator · 3D

METRO 2033 Redux
Shared: Atmospheric · Horror · Action

DEATH STRANDING DIRECTOR'S CUT
Shared: Walking Simulator · Atmospheric · Adventure

