Games like The Mermaid Mask
Games like The Mermaid Mask include Phoenix Wright: Ace Attorney Trilogy, No Case Should Remain Unsolved, Tangle Tower, The Roottrees are Dead, and Sherlock Holmes: The Devil's Daughter. We matched them by the tags players give The Mermaid Mask on Steam (Detective, Adventure, Point & Click, Puzzle, and Interactive Fiction): closest matches first, and among equally close ones the better-known games.

Phoenix Wright: Ace Attorney Trilogy
Shared: Detective · Visual Novel · Story Rich

No Case Should Remain Unsolved
Shared: Puzzle · Point & Click · Interactive Fiction

Tangle Tower
Shared: Detective · Point & Click · Puzzle

The Roottrees are Dead
Shared: Detective · Puzzle · Point & Click

Sherlock Holmes: The Devil's Daughter
Shared: Detective · Adventure · Puzzle

Sherlock Holmes: Crimes and Punishments
Shared: Detective · Adventure · Puzzle

The Case of the Golden Idol
Shared: Detective · Puzzle · Point & Click

Strange Horticulture
Shared: Puzzle · Detective · Point & Click

The Operator
Shared: Detective · Puzzle · Atmospheric

Chants of Sennaar
Shared: Adventure · Puzzle · Point & Click

Murdered: Soul Suspect
Shared: Detective · Adventure · Supernatural

The White Door
Shared: Adventure · Detective · Point & Click

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

The Rewinder
Shared: Adventure · Detective · Puzzle

Her Story
Shared: Detective · Interactive Fiction · Puzzle

The Wolf Among Us
Shared: Adventure · Detective · Story Rich

Sally Face - Episode One
Shared: Adventure · Puzzle · Story Rich

Murders on the Yangtze River
Shared: Detective · Adventure · Puzzle

Tails Noir
Shared: Detective · Adventure · Visual Novel

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

The Room
Shared: Puzzle · Point & Click · Adventure

Danganronpa: Trigger Happy Havoc
Shared: Detective · Visual Novel · Adventure

Trials of Innocence
Shared: Detective · Interactive Fiction · Visual Novel

The Séance of Blake Manor
Shared: Detective · Puzzle · Supernatural