Arrow keys to move in X and Y axis, and WASD to move in Z and W axis. Think of the yellow squares as the places you can move to. This project is a 4x4x4x4 hypercube, represented in 2D. In each 4x4 grid of small squares is the usual 2 axis (X,Y) you'd use on a graph. The 4x4 OF the 4x4 squares are pretty much the same, representing the remaining 2 axes (Z,W). Along the Z axis, imagine the left-most chunk is on top of the second chunk, which is on top of the 3rd chunk etc. The same thing goes for the W axis; the top-most chunk is on top of the one below it etc. The green square is the current coordinate, and the yellow squares are all directly neighbouring squares.
((IF YOU FIND ANY BUGS PLEASE TELL ME IN COMMENTS :D)) When writing coordinates on a 2D graph, with an X and a Y axis which are 90° to each other, you'd write it as X,Y. In 3D space, with an X, Y and Z axis all 90° to each other, you'd write the coordinates as X,Y,Z. The 4th dimension brings another axis 90° to all the previous, which we can call W. We write coordinates on a 4D graph as X,Y,Z,W. Here's a video explaining 4D space: https://www.youtube.com/watch?v=j-ixGKZlLVc
