Games like Zombie Claus
Games like Zombie Claus include Summer of '58, Fears to Fathom - Ironbark Lookout, Mouthwashing, Outlast, and SOMA. We matched them by the tags players give Zombie Claus on Steam (Horror, Thriller, Atmospheric, Psychological Horror, and Walking Simulator): closest matches first, and among equally close ones the better-known games.

Summer of '58
Shared: Horror · Thriller · Atmospheric

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

Mouthwashing
Shared: Horror · Psychological Horror · Atmospheric

Outlast
Shared: Horror · Atmospheric · Psychological Horror

SOMA
Shared: Horror · Atmospheric · Psychological Horror

Resident Evil 7 Biohazard
Shared: Horror · Atmospheric · First-Person

SILENT HILL 2
Shared: Horror · Psychological Horror · Atmospheric

Poppy Playtime
Shared: Horror · Psychological Horror · First-Person

Layers of Fear (2016)
Shared: Horror · Atmospheric · Psychological Horror

MiSide
Shared: Psychological Horror · Horror · Atmospheric

Lethal Company
Shared: Horror · First-Person · Psychological Horror

Backrooms: Escape Together
Shared: Horror · Psychological Horror · Atmospheric

Firewatch
Shared: Atmospheric · Walking Simulator · First-Person

Visage
Shared: Horror · Psychological Horror · Atmospheric

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

Outlast 2
Shared: Horror · Psychological Horror · Atmospheric

ROUTINE
Shared: Atmospheric · Psychological Horror · Horror

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

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

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

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

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

Resident Evil Requiem
Shared: Horror · Survival Horror · Zombies

The Beast Inside
Shared: Horror · First-Person · Psychological Horror