Games like When the Darkness comes
Games like When the Darkness comes include Poppy Playtime, Layers of Fear (2016), Mouthwashing, What Remains of Edith Finch, and No, I'm not a Human. We matched them by the tags players give When the Darkness comes on Steam (Psychological Horror, Free to Play, Walking Simulator, Indie, and First-Person): closest matches first, and among equally close ones the better-known games.

Poppy Playtime
Shared: Free to Play · Horror · Psychological Horror

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

Mouthwashing
Shared: Psychological Horror · Horror · Indie

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

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

SOMA
Shared: Psychological Horror · Horror · Atmospheric

Outlast
Shared: Psychological Horror · First-Person · Horror

Firewatch
Shared: Walking Simulator · Adventure · First-Person

The Beginner's Guide
Shared: Walking Simulator · Indie · First-Person

Blair Witch
Shared: Psychological Horror · Horror · Indie

Sally Face - Episode One
Shared: Psychological Horror · Indie · Horror

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

MiSide
Shared: Psychological Horror · First-Person · Horror

Dark Deception
Shared: Free to Play · Psychological Horror · Horror

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

Little Nightmares
Shared: Horror · Adventure · Atmospheric

Little Nightmares II
Shared: Horror · Psychological Horror · Adventure

Ultimate Custom Night
Shared: Free to Play · Horror · First-Person

Fran Bow
Shared: Psychological Horror · Horror · Indie

The Stanley Parable
Shared: Walking Simulator · Indie · First-Person

Layers of Fear 2 (2019)
Shared: Psychological Horror · Indie · Walking Simulator

Visage
Shared: Psychological Horror · Horror · First-Person

Awkward Dimensions Redux
Shared: Free to Play · Walking Simulator · Indie

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