Tic-tac-toe 3-Layer

Players take turns marking squares with X's and O's as usual. But this is a 3-dimensional grid now, which means that 3-in-a-row can be made horizontally, vertically, or diagonally on any of the three boards,

OR

vertically THROUGH the boards

OR

diagonally THROUGH the boards.

One Player Game
(vs. computer) Two Player Game
(take turns)