Games like GLASS
Games like GLASS include Firewatch, The Beginner's Guide, What Remains of Edith Finch, Mouthwashing, and The Stanley Parable. We matched them by the tags players give GLASS on Steam (Walking Simulator, RPG, 3D, First-Person, and Psychological): closest matches first, and among equally close ones the better-known games.

Firewatch
Shared: Walking Simulator · Atmospheric · First-Person

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

What Remains of Edith Finch
Shared: Walking Simulator · Atmospheric · Story Rich

Mouthwashing
Shared: Atmospheric · Story Rich · Walking Simulator

The Stanley Parable
Shared: Walking Simulator · First-Person · Psychological

Kingdom Come: Deliverance II
Shared: RPG · First-Person · Story Rich

Summer of '58
Shared: Walking Simulator · Atmospheric · First-Person

The Witcher 3: Wild Hunt — Remastered
Shared: RPG · Atmospheric · Story Rich

Cyberpunk 2077
Shared: RPG · Story Rich · First-Person

The Suicide of Rachel Foster
Shared: Walking Simulator · Atmospheric · Story Rich

Kingdom Come: Deliverance
Shared: RPG · First-Person · Story Rich

Amnesia: A Machine For Pigs
Shared: Walking Simulator · First-Person · Atmospheric

MiSide
Shared: First-Person · Story Rich · 3D

Layers of Fear (2016)
Shared: Walking Simulator · First-Person · Atmospheric

Fallout 4
Shared: RPG · Atmospheric · First-Person

Fallout: New Vegas
Shared: RPG · First-Person · Story Rich

CARIMARA: Beneath the forlorn limbs
Shared: Story Rich · 3D · Walking Simulator

Gone Home
Shared: Walking Simulator · First-Person · Atmospheric

Hellblade: Senua's Sacrifice
Shared: Psychological · Atmospheric · Story Rich

Quern - Undying Thoughts
Shared: Walking Simulator · Atmospheric · First-Person

POOLS
Shared: Walking Simulator · Atmospheric · First-Person

Before Your Eyes
Shared: First-Person · Walking Simulator · Story Rich

KARMA: The Dark World
Shared: Walking Simulator · First-Person · Atmospheric

The Painscreek Killings
Shared: Walking Simulator · Story Rich · Mystery