Games like Liminal Universe
Games like Liminal Universe include POOLS, The Exit 8, Dreamcore, Summer of '58, and Lethal Company. We matched them by the tags players give Liminal Universe on Steam (Exploration, Walking Simulator, Psychological Horror, 3D, and First-Person): closest matches first, and among equally close ones the better-known games.

POOLS
Shared: Walking Simulator · Psychological Horror · Exploration

The Exit 8
Shared: Exploration · Walking Simulator · Psychological Horror

Dreamcore
Shared: Exploration · Walking Simulator · Psychological Horror

Summer of '58
Shared: Psychological Horror · Walking Simulator · Horror

Lethal Company
Shared: First-Person · Exploration · Horror

Scanner Sombre
Shared: Exploration · Walking Simulator · Psychological Horror

September 7th
Shared: Exploration · Walking Simulator · Psychological Horror

SOMA
Shared: Psychological Horror · Horror · Exploration

Fears to Fathom - Ironbark Lookout
Shared: Psychological Horror · Exploration · Horror

Layers of Fear (2016)
Shared: Psychological Horror · Walking Simulator · Horror

Mouthwashing
Shared: Psychological Horror · Horror · Walking Simulator

MiSide
Shared: Psychological Horror · First-Person · Horror

Firewatch
Shared: Walking Simulator · Exploration · First-Person

Escape the Backrooms
Shared: Psychological Horror · Horror · Exploration

What Remains of Edith Finch
Shared: Walking Simulator · Exploration · First-Person

Psalm 5:9-13
Shared: Psychological Horror · Exploration · Walking Simulator

Still Wakes the Deep
Shared: Psychological Horror · Walking Simulator · Horror

ROUTINE
Shared: Psychological Horror · Sci-fi · Walking Simulator

Visage
Shared: Psychological Horror · Horror · First-Person

Subliminal
Shared: Psychological Horror · Realistic · First-Person

Iron Lung
Shared: Psychological Horror · Horror · First-Person

Platform 8
Shared: Psychological Horror · Walking Simulator · Exploration

Amnesia: A Machine For Pigs
Shared: Walking Simulator · Exploration · Horror

Millennium Dream
Shared: Walking Simulator · Exploration · Psychological Horror