Games like The Room 4: Old Sins
Games like The Room 4: Old Sins include The Room, The Room Three, The Room Two, The House of Da Vinci, and Outer Wilds. We matched them by the tags players give The Room 4: Old Sins on Steam (Puzzle, Mystery, Point & Click, Adventure, and Lovecraftian): closest matches first, and among equally close ones the better-known games.

The Room
Shared: Puzzle · Mystery · Point & Click

The Room Three
Shared: Puzzle · Mystery · Point & Click

The Room Two
Shared: Puzzle · Mystery · Point & Click

The House of Da Vinci
Shared: Puzzle · Mystery · Point & Click

Outer Wilds
Shared: Mystery · Adventure · Puzzle

Servant of the Lake
Shared: Puzzle · Point & Click · Adventure

Underground Blossom
Shared: Puzzle · Adventure · Point & Click

Cube Escape Collection
Shared: Puzzle · Mystery · Point & Click

Rusty Lake Paradise
Shared: Puzzle · Point & Click · Adventure

Blue Prince
Shared: Puzzle · Mystery · Singleplayer

Boxes: Lost Fragments
Shared: Puzzle · Mystery · Point & Click

Firewatch
Shared: Adventure · Mystery · Story Rich

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

Sally Face - Episode One
Shared: Puzzle · Mystery · Story Rich

Samsara Room
Shared: Puzzle · Adventure · Point & Click

Chants of Sennaar
Shared: Puzzle · Adventure · Point & Click

The Room VR: A Dark Matter
Shared: Puzzle · Adventure · Mystery

Poppy Playtime
Shared: Puzzle · Singleplayer · Mystery

Call of the Sea
Shared: Puzzle · Adventure · Lovecraftian

Return of the Obra Dinn
Shared: Mystery · Puzzle · Singleplayer

The Past Within
Shared: Puzzle · Mystery · Escape Room

Escape Simulator
Shared: Puzzle · Adventure · Escape Room

Twelve Minutes
Shared: Mystery · Puzzle · Adventure

The House of Da Vinci 3
Shared: Mystery · Puzzle · Point & Click