Games like The Old City: Leviathan
Games like The Old City: Leviathan include Firewatch, What Remains of Edith Finch, The Beginner's Guide, Outer Wilds, and Gone Home. We matched them by the tags players give The Old City: Leviathan on Steam (Walking Simulator, Adventure, Atmospheric, Exploration, and Indie): closest matches first, and among equally close ones the better-known games.

Firewatch
Shared: Adventure · Atmospheric · Walking Simulator

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

The Beginner's Guide
Shared: Walking Simulator · Atmospheric · Indie

Outer Wilds
Shared: Exploration · Adventure · Atmospheric

Gone Home
Shared: Walking Simulator · Exploration · Atmospheric

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

Amnesia: A Machine For Pigs
Shared: Walking Simulator · Atmospheric · Story Rich

Journey
Shared: Adventure · Atmospheric · Exploration

The Vanishing of Ethan Carter
Shared: Atmospheric · Walking Simulator · Exploration

INFRA
Shared: Exploration · Atmospheric · Walking Simulator

DEATH STRANDING DIRECTOR'S CUT
Shared: Walking Simulator · Atmospheric · Story Rich

The Forgotten City
Shared: Adventure · Exploration · Indie

NaissanceE
Shared: Exploration · Atmospheric · Walking Simulator

SOMA
Shared: Atmospheric · Story Rich · Exploration

The Talos Principle
Shared: Atmospheric · First-Person · Story Rich

Everybody's Gone to the Rapture
Shared: Walking Simulator · Atmospheric · Adventure

CARIMARA: Beneath the forlorn limbs
Shared: Adventure · Exploration · Story Rich

Valley
Shared: Adventure · Exploration · First-Person

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

The Witness
Shared: Exploration · First-Person · Atmospheric

Mouthwashing
Shared: Atmospheric · Story Rich · Walking Simulator

Obduction
Shared: Adventure · Exploration · Indie

Still Wakes the Deep
Shared: Walking Simulator · First-Person · Horror

Homesick
Shared: Atmospheric · Exploration · Walking Simulator