Games like Splinter
Games like Splinter include The Beginner's Guide, Manifold Garden, Antichamber, MiSide, and Layers of Fear (2016). We matched them by the tags players give Splinter on Steam (Experimental, First-Person, FMV, Psychedelic, and Atmospheric): closest matches first, and among equally close ones the better-known games.

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

Manifold Garden
Shared: First-Person · Experimental · Psychedelic

Antichamber
Shared: First-Person · Surreal · Indie

MiSide
Shared: First-Person · Atmospheric · 3D

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

Buckshot Roulette
Shared: First-Person · Singleplayer · 3D

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

Firewatch
Shared: Atmospheric · First-Person · Story Rich

Cyberpunk 2077
Shared: First-Person · Singleplayer · Atmospheric

Lucid Blocks
Shared: Psychedelic · Atmospheric · Surreal

Superliminal
Shared: First-Person · Surreal · Psychedelic

POOLS
Shared: Atmospheric · First-Person · Surreal

No, I'm not a Human
Shared: Atmospheric · First-Person · Singleplayer

Garten of Banban
Shared: First-Person · Singleplayer · 3D

Outlast
Shared: First-Person · Atmospheric · Singleplayer

Mouthwashing
Shared: Atmospheric · Story Rich · Indie

Moncage
Shared: Atmospheric · Experimental · Singleplayer

Dishonored
Shared: First-Person · Atmospheric · Singleplayer

Inscryption
Shared: Story Rich · Experimental · First-Person

Berry Bury Berry
Shared: First-Person · 3D · Surreal

A Story About My Uncle
Shared: First-Person · Atmospheric · Singleplayer

The Talos Principle
Shared: First-Person · Atmospheric · Singleplayer

Kingdom Come: Deliverance II
Shared: First-Person · Singleplayer · Story Rich

Bendy and the Ink Machine
Shared: First-Person · Singleplayer · Indie