Games like Pandamonium
Games like Pandamonium include Buckshot Roulette, Outlast, The Outlast Trials, Escape the Backrooms, and Poppy Playtime. We matched them by the tags players give Pandamonium on Steam (Action, Simulation, Psychological Horror, First-Person, and Horror): closest matches first, and among equally close ones the better-known games.

Buckshot Roulette
Shared: First-Person · Horror · Singleplayer

Outlast
Shared: First-Person · Horror · Psychological Horror

The Outlast Trials
Shared: Horror · Psychological Horror · First-Person

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

Poppy Playtime
Shared: Horror · Singleplayer · First-Person

MiSide
Shared: Psychological Horror · Horror · First-Person

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

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

Garten of Banban
Shared: Horror · Psychological Horror · First-Person

Outlast 2
Shared: Psychological Horror · Horror · First-Person

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

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

Bendy and the Dark Revival
Shared: Action · Horror · First-Person

KovaaK's
Shared: Action · Simulation · First-Person

Phasmophobia
Shared: Horror · Psychological Horror · First-Person

Resident Evil 7 Biohazard
Shared: Horror · First-Person · Singleplayer

Dark Deception
Shared: Horror · First-Person · Psychological Horror

CASE: Animatronics
Shared: Horror · First-Person · Psychological Horror

No, I'm not a Human
Shared: Psychological Horror · Horror · Singleplayer

Choo-Choo Charles
Shared: Horror · First-Person · Singleplayer

Thief Simulator
Shared: Simulation · Singleplayer · First-Person

Ultimate Custom Night
Shared: Horror · Singleplayer · First-Person

Five Nights at Freddy's 3
Shared: Horror · Singleplayer · First-Person

SILENT HILL: Townfall
Shared: Action · Horror · Psychological Horror