Games like The Trials 1
Games like The Trials 1 include Fallout 4, The Witness, Big Walk, Slime Rancher, and Outer Wilds. We matched them by the tags players give The Trials 1 on Steam (Puzzle, Adventure, Open World, Singleplayer, and Exploration): closest matches first, and among equally close ones the better-known games.

Fallout 4
Shared: Open World · Singleplayer · Adventure

The Witness
Shared: Puzzle · Open World · Exploration

Big Walk
Shared: Puzzle · Open World · Adventure

Slime Rancher
Shared: Adventure · Exploration · Singleplayer

Outer Wilds
Shared: Exploration · Adventure · Puzzle

Firewatch
Shared: Adventure · Atmospheric · Singleplayer

The Long Dark
Shared: Open World · Exploration · Singleplayer

Stray
Shared: Adventure · Singleplayer · Atmospheric

Rise of the Tomb Raider™
Shared: Adventure · Singleplayer · Open World

Hogwarts Legacy
Shared: Open World · Adventure · Singleplayer

Fallout: New Vegas
Shared: Open World · Singleplayer · Exploration

No Man's Sky
Shared: Open World · Exploration · Adventure

The Elder Scrolls IV: Oblivion Remastered
Shared: Open World · Adventure · Singleplayer

Slime Rancher 2
Shared: Open World · Singleplayer · Adventure

Riven
Shared: Puzzle · Adventure · Exploration

Flower
Shared: Adventure · Atmospheric · Relaxing

S.T.A.L.K.E.R. 2: Heart of Chornobyl - Standard Edition
Shared: Open World · Singleplayer · Atmospheric

AER Memories of Old
Shared: Adventure · Exploration · Open World

Spirit of the North
Shared: Adventure · Puzzle · Exploration

The Forest
Shared: Open World · Adventure · First-Person

Grand Theft Auto V Legacy
Shared: Open World · Adventure · First-Person

Starfield
Shared: Open World · Singleplayer · Exploration

Subnautica
Shared: Open World · Exploration · Singleplayer

Monument Valley
Shared: Puzzle · Adventure · Singleplayer