Games like DeathOmen
Games like DeathOmen include Five Nights at Freddy's, Outlast, No, I'm not a Human, Mouthwashing, and Poppy Playtime. We matched them by the tags players give DeathOmen on Steam (Horror, Psychological Horror, Atmospheric, Jump Scare, and Supernatural): closest matches first, and among equally close ones the better-known games.

Five Nights at Freddy's
Shared: Horror · Psychological Horror · Singleplayer

Outlast
Shared: Horror · Atmospheric · Psychological Horror

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

Mouthwashing
Shared: Horror · Psychological Horror · Atmospheric

Poppy Playtime
Shared: Horror · Psychological Horror · Singleplayer

Phasmophobia
Shared: Horror · Psychological Horror · Supernatural

SOMA
Shared: Horror · Psychological Horror · Atmospheric

Outlast 2
Shared: Horror · Psychological Horror · First-Person

MiSide
Shared: Psychological Horror · Horror · First-Person

DON'T SCREAM
Shared: Horror · Psychological Horror · Atmospheric

Summer of '58
Shared: Horror · Atmospheric · Psychological Horror

Buckshot Roulette
Shared: Horror · Dark · First-Person

Visage
Shared: Horror · Psychological Horror · Dark

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

Little Nightmares II
Shared: Horror · Atmospheric · Psychological Horror

Little Nightmares
Shared: Horror · Atmospheric · Singleplayer

Five Nights at Freddy's 2
Shared: Horror · Psychological Horror · Singleplayer

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

Firework
Shared: Horror · Psychological Horror · Atmospheric

The Mortuary Assistant
Shared: Horror · Supernatural · Atmospheric

Still Wakes the Deep
Shared: Horror · Psychological Horror · First-Person

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

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

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