Games like Do Not Disturb
Games like Do Not Disturb include Outlast, Garten of Banban, Buckshot Roulette, Escape the Backrooms, and Layers of Fear (2016). We matched them by the tags players give Do Not Disturb on Steam (Indie, Short, Action, Psychological Horror, and Walking Simulator): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · Psychological Horror · First-Person

Garten of Banban
Shared: Horror · Psychological Horror · Singleplayer

Buckshot Roulette
Shared: Indie · Horror · First-Person

Escape the Backrooms
Shared: Horror · Psychological Horror · First-Person

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

MiSide
Shared: Psychological Horror · Horror · Singleplayer

Poppy Playtime
Shared: Horror · Singleplayer · Psychological Horror

Slender: The Arrival
Shared: Indie · Horror · Psychological Horror

Dark Deception
Shared: Horror · Psychological Horror · Indie

Five Nights at Freddy's
Shared: Indie · Horror · Psychological Horror

Among the Sleep - Enhanced Edition
Shared: Indie · Horror · Walking Simulator

The Beast Inside
Shared: Horror · Action · Indie

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

The Beginner's Guide
Shared: Indie · Walking Simulator · Short

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

Spooky's Jump Scare Mansion: HD Renovation
Shared: Indie · Horror · Action

Garten of Banban 2
Shared: Horror · Psychological Horror · Singleplayer

Firewatch
Shared: Walking Simulator · Indie · Singleplayer

Mouthwashing
Shared: Psychological Horror · Indie · Horror

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

[Chillas Art] The Convenience Store
Shared: Indie · Psychological Horror · Horror

Neverending Nightmares
Shared: Indie · Psychological Horror · Horror

Iron Lung
Shared: Indie · Psychological Horror · Horror

Still Wakes the Deep
Shared: Psychological Horror · Horror · Walking Simulator