Too easy, and you always move first. Also, medium is more challenging than hard.

There are other free reversi/othello games, which include 2-player option, option to play a network player, option to go second, and a smarter AI.

To beat this game, take the corners and build from there, as your pieces cannot be flipped back. Avoid going one square diagonally In from the corner; if the AI goes there, make plans to capture the corner. In starting play, try to place your pieces in the center 4x4 area, especially in the four key corners there. Be careful playing on the edge, and be very cautious playing two counters on the edge separated by one empty square. Since many pieces can be flipped at once, try not getting too many counters in your color at the beginning of the game; this will limit the AIs choices.

Comet☄ about Black and White