Four-D Tic Tac Toe

The problem with 4D: it requires four players. Proof: Consider the first move P1 to be in a corner space. The number of "planes", where each plane is a 2D grid, in 2D is 1, in 3D is 7 and in 4D > 7. Consisting only a 3D cube within our hypercube, wlg: The first move by P2 can be anywhere. P1 plays to the same plane as their first move, and hence is only 1 step away from winning. P2 will block them. They can now play to a different plane, and again P2 will block. P1 can always play st. they can now win.

Decent implementation of the concept, but the problem is that there's still a huge advantage to moving first, even with the blocking moves. So when you move first, even the expert level is easily beatable and when you don't you just have to hope the computer makes a mistake.