The Game Boy Color version of Tennis looks like it packs in just as much exciting gameplay as its Nintendo 64 counterpart, titled Mario Tennis. The Camelot-developed game contains most of the Mario Tennis favorites, such as Yoshi, Peach, Luigi, Bowser, Wario, and Mario, as well as a few new characters. Similar to Mario Golf, you'll be able to use the GB Transfer Pak with the game, presumably to bring some of the non-Mario universe characters into the N64 version of the game.
GB Tennis Color (why the heck hasn't this been renamed to Mario Tennis GB yet?) is scheduled for a November release in Japan.