Games like Psalm 5:9-13
Games like Psalm 5:9-13 include Mouthwashing, What Remains of Edith Finch, SOMA, Firewatch, and Layers of Fear (2016). We matched them by the tags players give Psalm 5:9-13 on Steam (Psychological Horror, Horror, Indie, Exploration, and Mystery): closest matches first, and among equally close ones the better-known games.

Mouthwashing
Shared: Psychological Horror · Horror · Indie

What Remains of Edith Finch
Shared: Mystery · Walking Simulator · Exploration

SOMA
Shared: Psychological Horror · Horror · Atmospheric

Firewatch
Shared: Mystery · Walking Simulator · Atmospheric

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

Outlast
Shared: Horror · Psychological Horror · First-Person

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

Poppy Playtime
Shared: Horror · Psychological Horror · Mystery

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

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

Don't Play This
Shared: Psychological Horror · Indie · Horror

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

MiSide
Shared: Psychological Horror · Horror · First-Person

Outer Wilds
Shared: Exploration · Mystery · Atmospheric

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

The Park®
Shared: Psychological Horror · Horror · Walking Simulator

Psalm 2
Shared: Psychological Horror · Indie · Horror

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

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

Welcome to Kowloon
Shared: Horror · Psychological Horror · Atmospheric

Outlast 2
Shared: Psychological Horror · Horror · Gore

Visage
Shared: Psychological Horror · Horror · Indie

Lethal Company
Shared: Horror · Psychological Horror · Exploration

The Exit 8
Shared: Exploration · Horror · Psychological Horror