Empty

https://dustyroom.itch.io/empty

This is a relaxing, puzzle experience in which a 3D room is rotated. When objects blend into their surroundings, they disappear.

Genre: Puzzle.
Platforms: PC.
Difficulty: Not tricky to start with. Gets more complex later.
Age-related suggestions: No reading required, just the ability to rotate the screen with mouse.

Consider consulting detailed reviews before purchase. (But this one is “name your own price”, including free.)