Games like The Expansion
Games like The Expansion include Firewatch, Outer Wilds, Amnesia: Rebirth, Five Nights at Freddy's: Security Breach, and What Remains of Edith Finch. We matched them by the tags players give The Expansion on Steam (Exploration, Adventure, Action-Adventure, First-Person, and Indie): closest matches first, and among equally close ones the better-known games.

Firewatch
Shared: Adventure · Exploration · First-Person

Outer Wilds
Shared: Exploration · Adventure · Mystery

Amnesia: Rebirth
Shared: Action-Adventure · First-Person · Adventure

Five Nights at Freddy's: Security Breach
Shared: Horror · First-Person · Exploration

What Remains of Edith Finch
Shared: Exploration · First-Person · Adventure

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

The Long Dark
Shared: Exploration · Adventure · First-Person

Stray
Shared: Adventure · Exploration · Atmospheric

Lethal Company
Shared: First-Person · Horror · Exploration

The Forest
Shared: Adventure · Horror · First-Person

Poppy Playtime
Shared: Horror · First-Person · Singleplayer

Outlast
Shared: First-Person · Horror · Atmospheric

Slime Rancher
Shared: Exploration · Adventure · First-Person

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

Little Nightmares II
Shared: Adventure · Horror · Atmospheric

Thief Simulator
Shared: First-Person · Stealth · Adventure

DREDGE
Shared: Exploration · Adventure · Atmospheric

Little Nightmares
Shared: Adventure · Horror · Atmospheric

Hello Neighbor 2
Shared: Adventure · First-Person · Action-Adventure

PEAK
Shared: Adventure · Exploration · First-Person

Subnautica
Shared: Exploration · Horror · Adventure

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

Rise of the Tomb Raider™
Shared: Adventure · Exploration · Action-Adventure

Layers of Fear (2016)
Shared: Horror · First-Person · Atmospheric