Games like Ajnabee - The Unknown
Games like Ajnabee - The Unknown include What Remains of Edith Finch, Mouthwashing, Firewatch, SOMA, and Layers of Fear (2016). We matched them by the tags players give Ajnabee - The Unknown on Steam (Psychological Horror, Walking Simulator, Story Rich, Atmospheric, and Horror): closest matches first, and among equally close ones the better-known games.

What Remains of Edith Finch
Shared: Story Rich · Walking Simulator · Atmospheric

Mouthwashing
Shared: Psychological Horror · Story Rich · Horror

Firewatch
Shared: Story Rich · Walking Simulator · Atmospheric

SOMA
Shared: Psychological Horror · Horror · Story Rich

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

Amnesia: A Machine For Pigs
Shared: Walking Simulator · Story Rich · Horror

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

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

MiSide
Shared: Psychological Horror · Story Rich · Horror

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

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

Sally Face - Episode One
Shared: Psychological Horror · Story Rich · Horror

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

Hellblade: Senua's Sacrifice
Shared: Atmospheric · Story Rich · Female Protagonist

Martha Is Dead
Shared: Psychological Horror · Story Rich · Horror

Outer Wilds
Shared: Story Rich · Exploration · Atmospheric

SILENT HILL 2
Shared: Psychological Horror · Story Rich · Horror

Psalm 5:9-13
Shared: Psychological Horror · Horror · Walking Simulator

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

Luto
Shared: Psychological Horror · Walking Simulator · Story Rich

Dagon: by H. P. Lovecraft
Shared: Horror · Atmospheric · Psychological Horror

SILENT HILL f
Shared: Psychological Horror · Horror · Story Rich

The Suicide of Rachel Foster
Shared: Walking Simulator · Atmospheric · Story Rich

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