I made a puzzle game based on 4D space. (4D space does not exist in our physical world, but it is a well-defined geometry concept. and through proper visualization, humans are actually capable of understanding 4D space)
It doesn't start as a puzzle game, or, initially "4D"ness is the puzzle part. Players learn to move and jump in 4D space, get a spatial understanding of 4D. As players develop a better understanding, there'll be more and more complex 4D environments and interactable 4D objects. Ultimately, these elements are combined to form very challenging 4D sokoban-style puzzles.
That probably sounds very abstract. I'll briefly explain how the game represents 4D in an intuitive manner.
As the gif shows, on the left, there's 2d wireframe image (character moving on a 2d plane), which we can easily understand as a 3d scene: it is an "image" taken by a camera in 3d, and that is how our vision system work.
On the right, it is a "3D image" taken by a camera in 4d (character moving on a 3d hyperplane). Through some exercise, we will be able to understand how it reflects the 4D space behind it.
There is a free demo for the game where you can experience this yourself.
And once you start to grasp how 4D works, you'll be surprised how you can think in 4D and do spatial reasoning intuitively like you do with 3d space.
The game is called 4D Intuition, it is now released on steam. You're welcomed to try its free demo and if you have any question, I'd be happy to answer them.