Games like Night Janitor
Games like Night Janitor include Firewatch, Little Nightmares II, Little Nightmares, Layers of Fear (2016), and Outlast. We matched them by the tags players give Night Janitor on Steam (Adventure, Casual, Singleplayer, Atmospheric, and Horror): closest matches first, and among equally close ones the better-known games.

Firewatch
Shared: Adventure · Atmospheric · Singleplayer

Little Nightmares II
Shared: Adventure · Singleplayer · Horror

Little Nightmares
Shared: Adventure · Atmospheric · Horror

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

Outlast
Shared: Horror · Atmospheric · Singleplayer

Fears to Fathom - Woodbury Getaway
Shared: Adventure · Casual · Psychological Horror

BABBDI
Shared: Atmospheric · Casual · Walking Simulator

DISTRAINT 2
Shared: Horror · Psychological Horror · Atmospheric

SOMA
Shared: Horror · Atmospheric · Psychological Horror

[Nightmare Files] Clap Clap
Shared: Adventure · Horror · Atmospheric

What Remains of Edith Finch
Shared: Atmospheric · Adventure · Walking Simulator

The Medium
Shared: Adventure · Horror · Atmospheric

Poppy Playtime
Shared: Singleplayer · Horror · Psychological Horror

ROUTINE
Shared: Singleplayer · Atmospheric · Adventure

SILENT HILL 2
Shared: Horror · Psychological Horror · Atmospheric

Stray
Shared: Adventure · Singleplayer · Atmospheric

Fears to Fathom® - Scratch Creek
Shared: Adventure · Horror · Casual

[Chillas Art] The Convenience Store
Shared: Adventure · Horror · Casual

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

MiSide
Shared: Psychological Horror · Horror · Singleplayer

Getting Over It with Bennett Foddy
Shared: Singleplayer · Psychological Horror · Horror

Layers of Fear 2 (2019)
Shared: Horror · Psychological Horror · Atmospheric

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

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