Games like Explore The Backrooms
Games like Explore The Backrooms include Platform 8, [Chillas Art] The Closing Shift, Portal, The Talos Principle 2, and Portal 2. We matched them by the tags players give Explore The Backrooms on Steam (Action, Adventure, Simulation, Puzzle, and Walking Simulator): closest matches first, and among equally close ones the better-known games.

Platform 8
Shared: Adventure · Simulation · Walking Simulator

[Chillas Art] The Closing Shift
Shared: Adventure · Simulation · Action

Portal
Shared: Puzzle · 3D Platformer · Puzzle Platformer

The Talos Principle 2
Shared: Puzzle · Walking Simulator · Exploration

Portal 2
Shared: Puzzle · 3D Platformer · Action

The Exit 8
Shared: Puzzle · Walking Simulator · Exploration

I'm counting to 6...
Shared: Adventure · Simulation · Walking Simulator

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

Summon
Shared: Action · Simulation · Puzzle

Sonic Frontiers
Shared: Adventure · Action · 3D Platformer

Tomb Raider Game of the Year
Shared: Action · Adventure · Exploration

Indiana Jones and the Great Circle
Shared: Puzzle · Adventure · Action

Supraland
Shared: Adventure · Exploration · Puzzle

The Forest
Shared: Adventure · Action · Exploration

Killer Frequency
Shared: Adventure · Puzzle · Simulation

Kena: Bridge of Spirits
Shared: Action · Adventure · 3D Platformer

Human Fall Flat
Shared: Puzzle · Adventure · Action

Beside Myself
Shared: Adventure · Simulation · Walking Simulator

Scanner Sombre
Shared: Adventure · Walking Simulator · Exploration

Internet Cafe Simulator 2
Shared: Simulation · Exploration · 3D

BONEWORKS
Shared: Action · Adventure · Puzzle

A Plague Tale: Requiem
Shared: Action · Adventure · Exploration

Journey To The Savage Planet
Shared: Adventure · Action · Exploration

Steep™
Shared: Action · Simulation · Adventure