Games like Backrooms Project: The lost file
Games like Backrooms Project: The lost file include No, I'm not a Human, Little Nightmares II, Tiny Bunny, Poppy Playtime, and Outlast 2. We matched them by the tags players give Backrooms Project: The lost file on Steam (Adventure, Cinematic, Dark, Horror, and Psychological Horror): closest matches first, and among equally close ones the better-known games.

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

Little Nightmares II
Shared: Adventure · Horror · Dark

Tiny Bunny
Shared: Horror · Dark · Psychological Horror

Poppy Playtime
Shared: Horror · Dark · Psychological Horror

Outlast 2
Shared: Horror · Psychological Horror · Dark

Outlast
Shared: Horror · Psychological Horror · Adventure

Blair Witch
Shared: Adventure · Horror · Psychological Horror

Little Nightmares
Shared: Adventure · Horror · Dark

The Dark Pictures Anthology: Man of Medan
Shared: Adventure · Horror · Cinematic

Still Wakes the Deep
Shared: Horror · Psychological Horror · Dark

Fran Bow
Shared: Psychological Horror · Adventure · Horror

ROUTINE
Shared: Cinematic · Psychological Horror · Adventure

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

Mouthwashing
Shared: Horror · Psychological Horror · Dark

Little Misfortune
Shared: Psychological Horror · Adventure · Indie

INSIDE
Shared: Dark · Horror · Cinematic

The Quarry
Shared: Horror · Cinematic · Choices Matter

SOMA
Shared: Horror · Psychological Horror · Dark

The Casting of Frank Stone™
Shared: Horror · Adventure · Choices Matter

Detention
Shared: Horror · Psychological Horror · Adventure

Amnesia: The Dark Descent
Shared: Horror · Psychological Horror · Gore

Lucius
Shared: Adventure · Horror · Gore

Bramble: The Mountain King
Shared: Adventure · Cinematic · Horror

Visage
Shared: Horror · Dark · Psychological Horror