Games like Mysterious Castle
Games like Mysterious Castle include There Is No Game: Wrong Dimension, That's not my Neighbor, Hero of the Kingdom, Syberia, and The Room. We matched them by the tags players give Mysterious Castle on Steam (Adventure, Casual, and Point & Click): closest matches first, and among equally close ones the better-known games.

There Is No Game: Wrong Dimension
Shared: Adventure · Point & Click · Casual

That's not my Neighbor
Shared: Adventure · Casual · Point & Click

Hero of the Kingdom
Shared: Adventure · Casual · Point & Click

Syberia
Shared: Adventure · Point & Click · Casual

The Room
Shared: Point & Click · Adventure · Casual

DAVE THE DIVER
Shared: Casual · Adventure

Hero of the Kingdom II
Shared: Adventure · Casual · Point & Click

Broken Age
Shared: Adventure · Point & Click · Casual

Machinarium
Shared: Point & Click · Adventure · Casual

Boxes: Lost Fragments
Shared: Adventure · Point & Click · Casual

Florence
Shared: Casual · Adventure · Point & Click

The Wolf Among Us
Shared: Adventure · Point & Click · Casual

LUNA The Shadow Dust
Shared: Adventure · Casual · Point & Click

Lil' Guardsman
Shared: Adventure · Casual · Point & Click

Storyteller
Shared: Point & Click · Adventure · Casual

Chained Together
Shared: Adventure · Casual

Morphopolis
Shared: Point & Click · Casual · Adventure

Samorost 1
Shared: Point & Click · Casual · Adventure

Hero of the Kingdom III
Shared: Adventure · Casual · Point & Click

Tick Tock: A Tale for Two
Shared: Adventure · Casual · Point & Click

Return to Monkey Island
Shared: Adventure · Point & Click · Casual

Myst: Masterpiece Edition
Shared: Adventure · Casual · Point & Click

Neighbours back From Hell
Shared: Point & Click · Adventure · Casual

Frankenstein: Master of Death
Shared: Casual · Point & Click · Adventure