Games like Deep Frost
Games like Deep Frost include No, I'm not a Human, The Test, Sally Face - Episode One, Phasmophobia, and The Case of the Golden Idol. We matched them by the tags players give Deep Frost on Steam (Social Deduction, Psychological Horror, Mystery, Investigation, and Detective): closest matches first, and among equally close ones the better-known games.

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

The Test
Shared: Psychological Horror · Story Rich · Pixel Graphics

Sally Face - Episode One
Shared: Psychological Horror · Story Rich · Mystery

Phasmophobia
Shared: Psychological Horror · Horror · Investigation

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

SOMA
Shared: Psychological Horror · Story Rich · Horror

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

Raging Loop
Shared: Mystery · Psychological Horror · Story Rich

Return to Shironagasu Island
Shared: Mystery · Psychological Horror · Detective

MiSide
Shared: Psychological Horror · Story Rich · Horror

OMORI
Shared: Psychological Horror · Story Rich · Pixel Graphics

Back to the Dawn
Shared: Story Rich · Detective · Choices Matter

Oxenfree
Shared: Story Rich · Choices Matter · Mystery

Call of Cthulhu®
Shared: Psychological Horror · Detective · Mystery

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

Unheard - Voices of Crime
Shared: Mystery · Detective · Story Rich

Mouthwashing
Shared: Psychological Horror · Story Rich · Horror

The Painscreek Killings
Shared: Mystery · Investigation · Detective

The Test: Hypothesis Rising
Shared: Choices Matter · Psychological Horror · Mystery

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

DISTRAINT: Deluxe Edition
Shared: Psychological Horror · Story Rich · Pixel Graphics

Cube Escape Collection
Shared: Mystery · Psychological Horror · Story Rich

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

Danganronpa: Trigger Happy Havoc
Shared: Mystery · Detective · Psychological Horror