Reversi / Othello, but the board is a globe. Flanking lines that run off one edge come back in on the opposite side — in every direction. There are no corners and no edges to hide behind: any square can be flanked from the far side of the world.
How to play: click a highlighted cell to place a dark disc and flip the AI's discs between yours. Lines wrap around all four edges & both diagonals, so watch the whole board. Most discs when the grid fills up wins. If you have no move, your turn is passed.