Games like The Co-Exist Files
Games like The Co-Exist Files include Firework, Tiny Bunny, Mouthwashing, No, I'm not a Human, and Fears to Fathom - Ironbark Lookout. We matched them by the tags players give The Co-Exist Files on Steam (Visual Novel, Horror, Narrative, Comic Book, and Cinematic): closest matches first, and among equally close ones the better-known games.

Firework
Shared: Horror · Indie · Visual Novel

Tiny Bunny
Shared: Visual Novel · Horror · Atmospheric

Mouthwashing
Shared: Horror · Indie · Atmospheric

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

Fears to Fathom - Ironbark Lookout
Shared: Horror · Narrative · Atmospheric

Raging Loop
Shared: Visual Novel · Indie · Mystery

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

Outlast
Shared: Horror · Gore · Atmospheric

Poppy Playtime
Shared: Horror · Singleplayer · Indie

Detention
Shared: Horror · Indie · Atmospheric

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

Return to Shironagasu Island
Shared: Visual Novel · Horror · Mystery

INSIDE
Shared: Horror · Atmospheric · Indie

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

SOMA
Shared: Horror · Atmospheric · Psychological Horror

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

Outlast 2
Shared: Horror · Gore · Psychological Horror

Lobotomy Corporation | Monster Management Simulation
Shared: Horror · Gore · Psychological Horror

Little Nightmares
Shared: Horror · Atmospheric · Indie

MiSide
Shared: Horror · Psychological Horror · Atmospheric

Tales of the Black Forest
Shared: Horror · Visual Novel · Indie

DISTRAINT: Deluxe Edition
Shared: Horror · Indie · Psychological Horror

Dagon: by H. P. Lovecraft
Shared: Horror · Visual Novel · Atmospheric

The Quarry
Shared: Horror · Cinematic · Gore