Games like Mystery Box: Hidden Secrets
Games like Mystery Box: Hidden Secrets include The Room, Outer Wilds, Blue Prince, The House of Da Vinci, and The Room 4: Old Sins. We matched them by the tags players give Mystery Box: Hidden Secrets on Steam (Puzzle, Strategy, Exploration, Hidden Object, and Atmospheric): closest matches first, and among equally close ones the better-known games.

The Room
Shared: Puzzle · Mystery · Atmospheric

Outer Wilds
Shared: Exploration · Mystery · Puzzle

Blue Prince
Shared: Puzzle · Exploration · Mystery

The House of Da Vinci
Shared: Puzzle · Hidden Object · Exploration

The Room 4: Old Sins
Shared: Puzzle · Mystery · Hidden Object

The Room Two
Shared: Puzzle · Mystery · Hidden Object

The Room Three
Shared: Puzzle · Mystery · Atmospheric

The Witness
Shared: Puzzle · Exploration · First-Person

What Remains of Edith Finch
Shared: Atmospheric · Exploration · Mystery

Firewatch
Shared: Atmospheric · Mystery · Exploration

Quern - Undying Thoughts
Shared: Puzzle · Exploration · Atmospheric

Moncage
Shared: Puzzle · Atmospheric · Exploration

Boxes: Lost Fragments
Shared: Puzzle · Mystery · Atmospheric

Stray
Shared: Atmospheric · Exploration · Puzzle

Antichamber
Shared: Puzzle · Exploration · First-Person

Riven
Shared: Puzzle · Exploration · Atmospheric

Strange Horticulture
Shared: Puzzle · Mystery · Atmospheric

Obduction
Shared: Puzzle · Exploration · Mystery

The Talos Principle
Shared: Puzzle · Atmospheric · First-Person

INFRA
Shared: Puzzle · Exploration · Atmospheric

Poppy Playtime
Shared: Puzzle · First-Person · Mystery

Chants of Sennaar
Shared: Puzzle · Atmospheric · Adventure

Inside the Backrooms
Shared: Puzzle · Exploration · Atmospheric

Kairo
Shared: Puzzle · Exploration · Atmospheric