Othello Millennium is an adaptation of Othello/Reversi for Game Boy Color. The main draw is the Story Mode, where players select between a boy or girl as their character and play through a total of five levels of increasing difficulty against animated CPU opponents represented by animals. Before each match, players are asked a series of trivia questions pertaining to Othello, and some strategy questions where they are asked to choose the best move for a given board state; getting these questions right is not necessary to advance the game. They can also skip this mode entirely and just play a single game, selecting between 4 CPU opponents or choosing to play against Guest, which lets them play a two-player game (by handing off the game to a second player between moves).