Games like The Castle Mystery
Games like The Castle Mystery include Poppy Playtime, Little Nightmares II, Bendy and the Ink Machine, INSIDE, and The Room. We matched them by the tags players give The Castle Mystery on Steam (Horror, Multiple Endings, Atmospheric, Puzzle, and First-Person): closest matches first, and among equally close ones the better-known games.

Poppy Playtime
Shared: Horror · Puzzle · First-Person

Little Nightmares II
Shared: Horror · Puzzle · Atmospheric

Bendy and the Ink Machine
Shared: Horror · First-Person · Puzzle

INSIDE
Shared: Atmospheric · Horror · Multiple Endings

The Room
Shared: Puzzle · Atmospheric · Mystery

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

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

The Room Two
Shared: Puzzle · Atmospheric · Horror

No, I'm not a Human
Shared: Horror · Atmospheric · Multiple Endings

Amnesia: Rebirth
Shared: Puzzle · First-Person · Horror

Outlast
Shared: Horror · Atmospheric · First-Person

Little Nightmares
Shared: Horror · Atmospheric · Puzzle

The Room Three
Shared: Puzzle · Atmospheric · Mystery

Firework
Shared: Horror · Puzzle · Atmospheric

Hello Neighbor 2
Shared: Horror · Puzzle · First-Person

Garten of Banban 2
Shared: Horror · Puzzle · First-Person

Subliminal
Shared: Atmospheric · Horror · First-Person

Bendy and the Dark Revival
Shared: Horror · First-Person · Puzzle

Return of the Obra Dinn
Shared: Puzzle · Atmospheric · Mystery

Firewatch
Shared: Atmospheric · First-Person · Mystery

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

SOMA
Shared: Horror · Atmospheric · First-Person

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

MiSide
Shared: Horror · First-Person · Atmospheric