Games like Scarlet Idol
Games like Scarlet Idol include Phasmophobia, Escape the Backrooms, It Takes Two, Inside the Backrooms, and The Past Within. We matched them by the tags players give Scarlet Idol on Steam (Multiplayer, Puzzle, Psychological Horror, Online Co-Op, and Dungeon Crawler): closest matches first, and among equally close ones the better-known games.

Phasmophobia
Shared: Multiplayer · Co-op · Online Co-Op

Escape the Backrooms
Shared: Multiplayer · Co-op · Psychological Horror

It Takes Two
Shared: Multiplayer · Co-op · Puzzle

Inside the Backrooms
Shared: Multiplayer · Puzzle · Co-op

The Past Within
Shared: Co-op · Puzzle · Multiplayer

Backrooms: Escape Together
Shared: Multiplayer · Psychological Horror · Online Co-Op

Dead by Daylight
Shared: Multiplayer · Co-op · Horror

We Were Here Forever
Shared: Puzzle · Co-op · Multiplayer

Labyrinthine
Shared: Co-op · Multiplayer · Online Co-Op

We Were Here
Shared: Co-op · Puzzle · Multiplayer

PEAK
Shared: Multiplayer · Co-op · Online Co-Op

DEVOUR
Shared: Multiplayer · Online Co-Op · Co-op

Little Nightmares III
Shared: Co-op · Multiplayer · Puzzle

Little Nightmares II
Shared: Puzzle · Horror · Multiplayer

R.E.P.O.
Shared: Multiplayer · Co-op · Online Co-Op

Pacify
Shared: Multiplayer · Co-op · Online Co-Op

Tick Tock: A Tale for Two
Shared: Co-op · Puzzle · Online Co-Op

We Were Here Together
Shared: Puzzle · Online Co-Op · Co-op

Lethal Company
Shared: Co-op · Online Co-Op · Horror

Human Fall Flat
Shared: Co-op · Multiplayer · Puzzle

Demonologist
Shared: Multiplayer · Co-op · Psychological Horror

We Were Here Too
Shared: Puzzle · Co-op · Online Co-Op

RV There Yet?
Shared: Multiplayer · Co-op · Online Co-Op

A Way Out
Shared: Co-op · Online Co-Op · Multiplayer