Games like Level 13
Games like Level 13 include Dollmare, Phasmophobia, Summer of '58, Platform 8, and MiSide. We matched them by the tags players give Level 13 on Steam (Hidden Object, Investigation, Simulation, Walking Simulator, and 3D): closest matches first, and among equally close ones the better-known games.

Dollmare
Shared: Simulation · 3D · Horror

Phasmophobia
Shared: Horror · Investigation · Psychological Horror

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

Platform 8
Shared: Simulation · Walking Simulator · Hidden Object

MiSide
Shared: Psychological Horror · First-Person · Horror

No, I'm not a Human
Shared: Horror · Psychological Horror · First-Person

Mouthwashing
Shared: Horror · Psychological Horror · Walking Simulator

The Exit 8
Shared: Walking Simulator · Horror · First-Person

September 7th
Shared: Walking Simulator · Horror · First-Person

The Cabin Factory
Shared: Walking Simulator · Horror · Psychological Horror

Buckshot Roulette
Shared: First-Person · Horror · 3D

Welcome to Kowloon
Shared: Horror · Walking Simulator · Psychological Horror

Outlast
Shared: First-Person · Horror · Psychological Horror

Blair Witch
Shared: Horror · First-Person · Psychological Horror

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

[Chillas Art] Shinkansen 0 0
Shared: Investigation · Horror · Psychological Horror

Garten of Banban
Shared: Horror · First-Person · Psychological Horror

Locked Up
Shared: Simulation · Horror · First-Person

Visage
Shared: Horror · Psychological Horror · First-Person

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

From The Darkness
Shared: Horror · Psychological Horror · First-Person

The Boba Teashop
Shared: Horror · Walking Simulator · Simulation

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

Subliminal
Shared: Psychological Horror · Realistic · Horror