Games like No Case Should Remain Unsolved
Games like No Case Should Remain Unsolved include Her Story, The Case of the Golden Idol, The Mermaid Mask, There Is No Game: Wrong Dimension, and Refind Self: The Personality Test Game. We matched them by the tags players give No Case Should Remain Unsolved on Steam (Investigation, Puzzle, Interactive Fiction, Visual Novel, and Point & Click): closest matches first, and among equally close ones the better-known games.

Her Story
Shared: Investigation · Interactive Fiction · Puzzle

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

The Mermaid Mask
Shared: Puzzle · Interactive Fiction · Point & Click

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

Refind Self: The Personality Test Game
Shared: Interactive Fiction · Visual Novel · Story Rich

Tails Noir
Shared: Visual Novel · Interactive Fiction · Pixel Graphics

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

Desktop Explorer
Shared: Puzzle · Investigation · Point & Click

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

Murders on the Yangtze River
Shared: Puzzle · Story Rich · Adventure

Lay a Beauty to Rest: The Darkness Peach Blossom Spring
Shared: Visual Novel · Investigation · Interactive Fiction

Murder by Numbers
Shared: Investigation · Puzzle · Visual Novel

Kathy Rain: Director’s Cut
Shared: Point & Click · Investigation · Puzzle

Until Then
Shared: Visual Novel · Interactive Fiction · Story Rich

The Operator
Shared: Investigation · Puzzle · Detective

Papers, Please
Shared: Point & Click · Puzzle · Pixel Graphics

Tales of the Black Forest
Shared: Pixel Graphics · Story Rich · Adventure

OPUS: Echo of Starsong - Full Bloom Edition
Shared: Visual Novel · Interactive Fiction · Story Rich

The Darkside Detective: A Fumble in the Dark
Shared: Point & Click · Puzzle · Story Rich

OneShot
Shared: Story Rich · Puzzle · Pixel Graphics

Hymer 2000
Shared: Puzzle · Visual Novel · Story Rich

Trials of Innocence
Shared: Interactive Fiction · Visual Novel · Story Rich

7 Days to End with You
Shared: Puzzle · Visual Novel · Investigation

Tangle Tower
Shared: Puzzle · Point & Click · Visual Novel