Games like The Hungry Fly
Games like The Hungry Fly include Mouthwashing, Firewatch, What Remains of Edith Finch, SOMA, and Layers of Fear (2016). We matched them by the tags players give The Hungry Fly on Steam (Adventure, Horror, Surreal, Psychological Horror, and Story Rich): closest matches first, and among equally close ones the better-known games.

Mouthwashing
Shared: Horror · Psychological Horror · Story Rich

Firewatch
Shared: Adventure · Story Rich · Atmospheric

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

SOMA
Shared: Horror · Psychological Horror · Story Rich

Layers of Fear (2016)
Shared: Horror · Psychological Horror · Adventure

Outlast
Shared: Horror · Psychological Horror · First-Person

Amnesia: A Machine For Pigs
Shared: Horror · Story Rich · Psychological Horror

Still Wakes the Deep
Shared: Horror · Psychological Horror · Story Rich

Outlast 2
Shared: Horror · Psychological Horror · First-Person

Outer Wilds
Shared: Adventure · Exploration · Story Rich

MiSide
Shared: Psychological Horror · Horror · Story Rich

Resident Evil 7 Biohazard
Shared: Horror · First-Person · Psychological Horror

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

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

Fran Bow
Shared: Psychological Horror · Horror · Adventure

Little Nightmares II
Shared: Adventure · Horror · Psychological Horror

The Beginner's Guide
Shared: Story Rich · Adventure · First-Person

The Beast Inside
Shared: Adventure · Horror · First-Person

Little Nightmares
Shared: Horror · Adventure · Atmospheric

Amnesia: The Dark Descent
Shared: Horror · Psychological Horror · Adventure

Visage
Shared: Horror · Psychological Horror · Adventure

Detention
Shared: Horror · Psychological Horror · Adventure

Blair Witch
Shared: Adventure · Horror · Psychological Horror

The Park®
Shared: Horror · Psychological Horror · Adventure