Games like The Unclosed Case
Games like The Unclosed Case include Unheard - Voices of Crime, Sherlock Holmes: The Devil's Daughter, No, I'm not a Human, Raging Loop, and Heavy Rain. We matched them by the tags players give The Unclosed Case on Steam (Detective, Psychological Horror, Thriller, Mystery, and Investigation): closest matches first, and among equally close ones the better-known games.

Unheard - Voices of Crime
Shared: Detective · Thriller · Mystery

Sherlock Holmes: The Devil's Daughter
Shared: Detective · Mystery · Story Rich

No, I'm not a Human
Shared: Psychological Horror · Choices Matter · Story Rich

Raging Loop
Shared: Psychological Horror · Mystery · Detective

Heavy Rain
Shared: Detective · Story Rich · Choices Matter

L.A. Noire
Shared: Detective · Mystery · Story Rich

Sherlock Holmes: Crimes and Punishments
Shared: Detective · Mystery · Investigation

The Test
Shared: Psychological Horror · Story Rich · Psychological

Return of the Obra Dinn
Shared: Detective · Mystery · Story Rich

Mouthwashing
Shared: Psychological Horror · Story Rich · Atmospheric

The Case of the Golden Idol
Shared: Detective · Mystery · Investigation

Sherlock Holmes Chapter One
Shared: Detective · Mystery · Story Rich

Firewatch
Shared: Mystery · Story Rich · Atmospheric

The Forgotten City
Shared: Mystery · Investigation · Story Rich

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

The Painscreek Killings
Shared: Detective · Mystery · Investigation

The Operator
Shared: Detective · Investigation · Mystery

Oxenfree
Shared: Story Rich · Choices Matter · Mystery

The Bridge Curse 2: The Extrication
Shared: Psychological Horror · Mystery · Thriller

Phasmophobia
Shared: Psychological Horror · Detective · Investigation

The Test: Hypothesis Rising
Shared: Psychological Horror · Choices Matter · Story Rich

The Wolf Among Us
Shared: Detective · Story Rich · Choices Matter

MiSide
Shared: Psychological Horror · Story Rich · Thriller

Danganronpa 2: Goodbye Despair
Shared: Detective · Mystery · Psychological Horror