For those who prefer a single-player experience, or at least one to practice with to hone one's skills in preparation for a heads-up match against another human opponent, and if a little Japanese text won't scare you off, then give Taro Ito's GameDesign Flash implementation of Hanafuda a try.
Dice Wars is a unique new turn-based strategy game from Japan. Using nothing but dice and a randomly generated territory map made of hexagons, the game is similar in gameplay to that of the board game, Risk, though much simpler and quicker to play. The objective is to conquer all territories and eliminate all your opponents by attacking them with dice.
The modest and lackluster appearance of this game hides well the exceptional gameplay beneath its surface. And yet with the very first serve across the net, one can immediately tell this is no retro game of Pong. Challenging and exciting, this is the latest game by the very talented Taro Ito of GameDesign in Japan. Arigatoo gozaimasu!