Games like Lost Sanity: Cthulhu
Games like Lost Sanity: Cthulhu include Escape the Backrooms, Poppy Playtime, SOMA, Five Nights at Freddy's: Security Breach, and Outlast. We matched them by the tags players give Lost Sanity: Cthulhu on Steam (Lovecraftian, Horror, Psychological Horror, Mystery, and Adventure): closest matches first, and among equally close ones the better-known games.

Escape the Backrooms
Shared: Horror · Psychological Horror · Survival Horror

Poppy Playtime
Shared: Horror · Psychological Horror · Survival Horror

SOMA
Shared: Horror · Psychological Horror · Survival Horror

Five Nights at Freddy's: Security Breach
Shared: Horror · Survival Horror · Adventure

Outlast
Shared: Horror · Psychological Horror · Survival Horror

SILENT HILL f
Shared: Horror · Psychological Horror · Survival Horror

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

Amnesia: Rebirth
Shared: Horror · Adventure · Lovecraftian

The Beast Inside
Shared: Horror · Adventure · Survival Horror

Resident Evil Village
Shared: Horror · Survival Horror · Action

The Evil Within 2
Shared: Horror · Psychological Horror · Survival Horror

Resident Evil Requiem
Shared: Horror · Survival Horror · Action

What Remains of Edith Finch
Shared: Mystery · Story Rich · Adventure

Resident Evil 7 Biohazard
Shared: Horror · Survival Horror · Psychological Horror

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

DREDGE
Shared: Lovecraftian · Adventure · Mystery

Penumbra Overture
Shared: Horror · Adventure · Survival Horror

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

Bendy and the Dark Revival
Shared: Horror · Adventure · Survival Horror

Amnesia: A Machine For Pigs
Shared: Horror · Psychological Horror · Mystery

Darkwood
Shared: Horror · Psychological Horror · Adventure

Outlast 2
Shared: Horror · Psychological Horror · Survival Horror

Lethal Company
Shared: Horror · Survival Horror · Psychological Horror

Penumbra: Black Plague Gold Edition
Shared: Horror · Psychological Horror · Adventure