Jungle Emperor Leo (1999)

Jungle Emperor Leo was a 1997 movie based on the 1950's manga by Osamu Tezuka, Kimba the White Lion (incidentally, the inspiration for Disney's The Lion King). Nintendo secured the rights to develop a game based on the movie which was announced for the 64DD. The game appears to have been an action-adventure title starring characters from the movie and manga, but very little footage of the game was shown, so details are scarce.