Games like Crime Detective: Red Flags
Games like Crime Detective: Red Flags include Phasmophobia, MiSide, Poppy Playtime, Sally Face - Episode One, and Outlast. We matched them by the tags players give Crime Detective: Red Flags on Steam (Psychological Horror, Horror, Detective, Adventure, and Realistic): closest matches first, and among equally close ones the better-known games.

Phasmophobia
Shared: Horror · Psychological Horror · Detective

MiSide
Shared: Psychological Horror · Horror · First-Person

Poppy Playtime
Shared: Horror · Psychological Horror · Dark

Sally Face - Episode One
Shared: Psychological Horror · Horror · Dark

Outlast
Shared: Horror · Psychological Horror · First-Person

Little Nightmares II
Shared: Horror · Adventure · Psychological Horror

Demonologist
Shared: Horror · Psychological Horror · Dark

SOMA
Shared: Psychological Horror · Horror · Dark

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

Mouthwashing
Shared: Psychological Horror · Horror · Dark

Subliminal
Shared: Psychological Horror · Realistic · Horror

Little Nightmares
Shared: Horror · Adventure · Dark

Visage
Shared: Psychological Horror · Horror · Dark

Welcome to Kowloon
Shared: Horror · Psychological Horror · Adventure

Layers of Fear (2016)
Shared: Psychological Horror · Horror · Adventure

The Death | Thần Trùng
Shared: Psychological Horror · Horror · Adventure

Fears to Fathom - Ironbark Lookout
Shared: Psychological Horror · Horror · Adventure

Outlast 2
Shared: Psychological Horror · Horror · Dark

Call of Cthulhu®
Shared: Horror · Psychological Horror · Detective

Backrooms: Escape Together
Shared: Horror · Psychological Horror · Realistic

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

From The Darkness
Shared: Psychological Horror · Horror · Dark

Summer of '58
Shared: Horror · Psychological Horror · Thriller

Escape the Backrooms
Shared: Horror · Psychological Horror · Adventure