Inter-Dimensional Chess, or 4D Chess, is a Unity game in development about playing Chess in 4 spatial dimensions. This might be hard to wrap your head around, so I instead invite you to take a look at the following gameplay:
Here we can see the typical 3 dimensions at play, not that playing chess in 3D is typical, mind you.
Here I showcase the 6 dimensions in this 6x6x3x6 board.
Here we can see how weird slicing the 4D space into 3D chunks can get, by checking all the possible moves of our tower.
This clip shows how playing in a 3D chunk of the 4D space is rather simple.
But yes, things get quite hectic once you realize you have to take the entire board into account.