Games like Diagnosis: Room 101
Games like Diagnosis: Room 101 include Five Nights at Freddy's: Security Breach, Five Nights at Freddy's: Secret of the Mimic, Indiana Jones and the Great Circle, Slime Rancher, and Crimson Desert Enhanced. We matched them by the tags players give Diagnosis: Room 101 on Steam (Adventure, Action-Adventure, 3D, First-Person, and Dialogue Heavy): closest matches first, and among equally close ones the better-known games.

Five Nights at Freddy's: Security Breach
Shared: Singleplayer · First-Person · Adventure

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

Indiana Jones and the Great Circle
Shared: Action-Adventure · First-Person · Adventure

Slime Rancher
Shared: Adventure · Exploration · First-Person

Crimson Desert Enhanced
Shared: Adventure · Singleplayer · Exploration

Rise of the Tomb Raider™
Shared: Adventure · Singleplayer · Action-Adventure

Firewatch
Shared: Adventure · First-Person · Singleplayer

Escape the Backrooms
Shared: First-Person · Adventure · 3D

Grand Theft Auto V Legacy
Shared: Adventure · First-Person · Crime

PEAK
Shared: Adventure · First-Person · 3D

Tomb Raider Game of the Year
Shared: Adventure · Singleplayer · Action-Adventure

SILENT HILL: Townfall
Shared: Adventure · First-Person · Action-Adventure

Sonic Frontiers
Shared: Adventure · Action-Adventure · Singleplayer

Amnesia: Rebirth
Shared: Action-Adventure · First-Person · Adventure

Atomic Heart
Shared: Adventure · Action-Adventure · Singleplayer

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

Crime Scene Cleaner
Shared: First-Person · Singleplayer · Crime

Far Cry® 6
Shared: Action-Adventure · Adventure · First-Person

Fallout 4
Shared: Adventure · Singleplayer · Exploration

Thief Simulator
Shared: Singleplayer · First-Person · Adventure

The Elder Scrolls IV: Oblivion Remastered
Shared: Adventure · Singleplayer · First-Person

Resident Evil Requiem
Shared: First-Person · Action-Adventure · Singleplayer

Tomb Raider I-III Remastered Starring Lara Croft
Shared: Action-Adventure · Adventure · 3D

The Room 4: Old Sins
Shared: Adventure · Singleplayer · Hidden Object