Games like Liar Masks
Games like Liar Masks include MiSide, Layers of Fear (2016), The Cabin Factory, No, I'm not a Human, and Firewatch. We matched them by the tags players give Liar Masks on Steam (Horror, Psychological Horror, Walking Simulator, Hidden Object, and Investigation): closest matches first, and among equally close ones the better-known games.

MiSide
Shared: Psychological Horror · Horror · Singleplayer

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

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

No, I'm not a Human
Shared: Horror · Psychological Horror · Choices Matter

Firewatch
Shared: Walking Simulator · Adventure · Atmospheric

Blair Witch
Shared: Horror · Psychological Horror · Adventure

Outlast
Shared: Horror · Psychological Horror · First-Person

Mouthwashing
Shared: Horror · Psychological Horror · Walking Simulator

Visage
Shared: Horror · Psychological Horror · Walking Simulator

What Remains of Edith Finch
Shared: Walking Simulator · Adventure · Psychological Horror

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

SOMA
Shared: Horror · Psychological Horror · Atmospheric

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

Platform 8
Shared: Psychological Horror · Walking Simulator · Adventure

Poppy Playtime
Shared: Horror · Psychological Horror · Singleplayer

Little Nightmares II
Shared: Horror · Adventure · Psychological Horror

Killer Frequency
Shared: Horror · Adventure · Walking Simulator

Little Nightmares
Shared: Horror · Adventure · Singleplayer

[Chillas Art] The Convenience Store
Shared: Horror · Psychological Horror · Adventure

Scanner Sombre
Shared: Horror · Walking Simulator · Psychological Horror

The Beast Inside
Shared: Horror · Adventure · Psychological Horror

Garten of Banban
Shared: Horror · Psychological Horror · Singleplayer

The Test
Shared: Psychological Horror · Simulation · Horror

Phasmophobia
Shared: Horror · Psychological Horror · Investigation