Games like Marginal act
Games like Marginal act include Firewatch, Little Nightmares, Hellblade: Senua's Sacrifice, Outer Wilds, and Tiny Bunny. We matched them by the tags players give Marginal act on Steam (Adventure, Horror, Atmospheric, Story Rich, and Time Travel): closest matches first, and among equally close ones the better-known games.

Firewatch
Shared: Adventure · Atmospheric · Story Rich

Little Nightmares
Shared: Horror · Adventure · Atmospheric

Hellblade: Senua's Sacrifice
Shared: Atmospheric · Story Rich · Adventure

Outer Wilds
Shared: Adventure · Story Rich · Atmospheric

Tiny Bunny
Shared: Horror · Atmospheric · Story Rich

Little Nightmares II
Shared: Adventure · Horror · Atmospheric

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

Five Nights at Freddy's: Into the Pit
Shared: Horror · Adventure · 2D

Twelve Minutes
Shared: Adventure · Story Rich · Time Travel

What Remains of Edith Finch
Shared: Atmospheric · Story Rich · Adventure

SOMA
Shared: Horror · Atmospheric · Story Rich

Finding Paradise
Shared: Adventure · Story Rich · 2D

SILENT HILL 2
Shared: Horror · Story Rich · Atmospheric

Stray
Shared: Adventure · Atmospheric · Exploration

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

Hollow Knight
Shared: 2D · Adventure · Atmospheric

DISTRAINT: Deluxe Edition
Shared: Horror · Adventure · Story Rich

INSIDE
Shared: Atmospheric · Horror · Story Rich

A Plague Tale: Innocence
Shared: Adventure · Story Rich · Atmospheric

Amnesia: A Machine For Pigs
Shared: Horror · Atmospheric · Story Rich

Fran Bow
Shared: Story Rich · Horror · Adventure

Impostor Factory
Shared: Adventure · Story Rich · 2D

Night in the Woods
Shared: Adventure · Story Rich · Atmospheric

The Cat Lady
Shared: Horror · Adventure · Story Rich