Games like School 666
Games like School 666 include Phasmophobia, Escape the Backrooms, Lethal Company, Backrooms: Escape Together, and Pacify. We matched them by the tags players give School 666 on Steam (Horror, Online Co-Op, Realistic, Psychological Horror, and Adventure): closest matches first, and among equally close ones the better-known games.

Phasmophobia
Shared: Horror · Online Co-Op · Psychological Horror

Escape the Backrooms
Shared: Horror · Online Co-Op · Psychological Horror

Lethal Company
Shared: Horror · Online Co-Op · First-Person

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

Pacify
Shared: Horror · Online Co-Op · Psychological Horror

Zort
Shared: Horror · Online Co-Op · Psychological Horror

PEAK
Shared: Online Co-Op · Adventure · First-Person

Ready or Not
Shared: Realistic · Horror · Psychological Horror

Labyrinthine
Shared: Horror · Online Co-Op · Psychological Horror

Content Warning
Shared: Horror · Online Co-Op · Psychological Horror

Inside the Backrooms
Shared: Horror · Psychological Horror · Online Co-Op

Demonologist
Shared: Horror · Online Co-Op · Psychological Horror

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

R.E.P.O.
Shared: Horror · Online Co-Op · First-Person

Hospital 666
Shared: Horror · Online Co-Op · Psychological Horror

Fears to Fathom® - Scratch Creek
Shared: Horror · Psychological Horror · Adventure

Nuclear Nightmare
Shared: Online Co-Op · Horror · Psychological Horror

Poppy Playtime
Shared: Horror · First-Person · Psychological Horror

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

Subliminal
Shared: Realistic · Psychological Horror · Horror

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

Outlast
Shared: Horror · First-Person · Psychological Horror

Ghost Janitors
Shared: Horror · Online Co-Op · Psychological Horror

KLETKA
Shared: Horror · Online Co-Op · First-Person