Games like Lonely Christmas
Games like Lonely Christmas include MiSide, Platform 8, Summer of '58, Layers of Fear (2016), and Fears to Fathom - Ironbark Lookout. We matched them by the tags players give Lonely Christmas on Steam (Thriller, First-Person, Hidden Object, Psychological Horror, and Walking Simulator): closest matches first, and among equally close ones the better-known games.

MiSide
Shared: Psychological Horror · First-Person · Story Rich

Platform 8
Shared: Psychological Horror · Walking Simulator · Hidden Object

Summer of '58
Shared: Thriller · Psychological Horror · First-Person

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

Fears to Fathom - Ironbark Lookout
Shared: Psychological Horror · Thriller · First-Person

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

Dollmare
Shared: First-Person · Simulation · Psychological Horror

Mouthwashing
Shared: Psychological Horror · Story Rich · Walking Simulator

April 24th
Shared: Thriller · Psychological Horror · Simulation

Firewatch
Shared: First-Person · Walking Simulator · Story Rich

Superliminal
Shared: First-Person · Thriller · Puzzle

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

Father's Day
Shared: Psychological Horror · Thriller · Walking Simulator

Find Yourself
Shared: Simulation · Walking Simulator · First-Person

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

September 7th
Shared: First-Person · Psychological Horror · Walking Simulator

The Cabin Factory
Shared: Psychological Horror · Walking Simulator · First-Person

The Exit 8
Shared: Walking Simulator · Psychological Horror · First-Person

The Death | Thần Trùng
Shared: Psychological Horror · First-Person · Realistic

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

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

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

Subliminal
Shared: Psychological Horror · Thriller · Realistic

SOMA
Shared: Psychological Horror · Story Rich · First-Person