Games like YetiParty
Games like YetiParty include Outlast, Layers of Fear (2016), Firewatch, Mouthwashing, and SOMA. We matched them by the tags players give YetiParty on Steam (Parody , Horror, Atmospheric, Memes, and Dark Comedy): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · Atmospheric · Psychological Horror

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

Firewatch
Shared: Atmospheric · Adventure · Walking Simulator

Mouthwashing
Shared: Horror · Atmospheric · Psychological Horror

SOMA
Shared: Horror · Atmospheric · Psychological Horror

Little Nightmares
Shared: Horror · Atmospheric · Adventure

Little Nightmares II
Shared: Horror · Adventure · Atmospheric

Still Wakes the Deep
Shared: Horror · Atmospheric · Psychological Horror

Blair Witch
Shared: Horror · Adventure · Atmospheric

Visage
Shared: Horror · Atmospheric · Psychological Horror

Sally Face - Episode One
Shared: Horror · Atmospheric · Adventure

Iron Lung
Shared: Horror · Atmospheric · Psychological Horror

MiSide
Shared: Horror · Psychological Horror · Atmospheric

What Remains of Edith Finch
Shared: Atmospheric · Walking Simulator · Adventure

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

Welcome to Kowloon
Shared: Horror · Atmospheric · Adventure

Poppy Playtime
Shared: Horror · Psychological Horror · Adventure

Fears to Fathom - Ironbark Lookout
Shared: Horror · Atmospheric · Adventure

Among the Sleep - Enhanced Edition
Shared: Horror · Atmospheric · Adventure

The Cabin Factory
Shared: Horror · Atmospheric · Walking Simulator

Scanner Sombre
Shared: Horror · Atmospheric · Walking Simulator

Amnesia: The Dark Descent
Shared: Horror · Atmospheric · Psychological Horror

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

Phasmophobia
Shared: Horror · Psychological Horror · Supernatural