Games like The Gazebo
Games like The Gazebo include Five Nights at Freddy's: Security Breach, MiSide, Outlast, No, I'm not a Human, and Firewatch. We matched them by the tags players give The Gazebo on Steam (Horror, Singleplayer, Atmospheric, Multiple Endings, and Casual): closest matches first, and among equally close ones the better-known games.

Five Nights at Freddy's: Security Breach
Shared: Horror · Singleplayer · Multiple Endings

MiSide
Shared: Horror · Singleplayer · First-Person

Outlast
Shared: Horror · Atmospheric · First-Person

No, I'm not a Human
Shared: Horror · Singleplayer · Atmospheric

Firewatch
Shared: Atmospheric · Singleplayer · Adventure

Poppy Playtime
Shared: Horror · Singleplayer · First-Person

Little Nightmares
Shared: Horror · Atmospheric · Singleplayer

INSIDE
Shared: Atmospheric · Horror · Singleplayer

The Room
Shared: Atmospheric · Singleplayer · Horror

Resident Evil 7 Biohazard
Shared: Horror · Singleplayer · First-Person

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

Five Nights at Freddy's
Shared: Horror · Singleplayer · First-Person

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

That's not my Neighbor
Shared: Horror · Casual · Singleplayer

The Forest
Shared: Horror · First-Person · Adventure

Five Nights at Freddy's: Secret of the Mimic
Shared: Horror · First-Person · Adventure

The Hat Man: Shadow Ward
Shared: Horror · Atmospheric · First-Person

Little Nightmares II
Shared: Horror · Singleplayer · Atmospheric

Escape the Backrooms
Shared: Horror · First-Person · Singleplayer

SchoolBoy Runaway
Shared: Horror · Singleplayer · Adventure

Slime Rancher 2
Shared: Singleplayer · First-Person · Casual

Subliminal
Shared: Singleplayer · Atmospheric · Horror

Lethal Company
Shared: Horror · First-Person · Atmospheric

Bendy and the Dark Revival
Shared: Horror · Singleplayer · First-Person