The Legend of Zelda: The Third Oracle [unofficial title]

Originally part of what became the Game Boy Color Legend of Zelda: Oracle series (Oracle of Seasons and Oracle of Ages), this unnamed game was originally to be part three of an interconnected series of games called the Tri-Force Series (although what connection the storyline was to have to the Tri-Force itself is unknown, since Nintendo later played down the Tri-Force connection and the final GBC games did not center on the hunt for or use of the Tri-Force). One game was to focus on action (Chapter of Power), one was to focus on puzzles (Chapter of Wisdom), while the gameplay focus of the third (Chapter of Courage) was never officially announced. Each was also to have a theme -- The Tale of Power was about the four seasons, with the Rod of the Seasons able to change the seasons which then change the game areas; The Tale of Wisdom was to use a color theme, with various events and areas and tools built around certain colors; The Tale of Courage was to have the theme of time, where you could need to use morning, noon, evening and night in order to solve various riddles in this game. Each was also to have its own Oracle as the pivotal character of the story -- Din in the Tale of Power, Nayru in the Tale of Courage, and the lost Oracle Farore in Tale of Wisdom. All three games were to use Nintendo anticipated-at-the-time cellphone adapter technology for some form of data transfer. The plan at the time was to stagger the release of each game by six weeks to build anticipation for each new game and its cross-link compatibility.

Later in development, this series of Zelda games and its three titles were given a new story concept the official name, The Legend of Zelda: Mystical Seed of Power, Mystical Seed of Courage, and Mystical Seed of Wisdom. All three were designed in part by Capcom's Flagship in collaboration with Nintendo (the story scenario was conceived by Flagship, and programming and design was handled by the outside team.) Nintendo originally commissioned six Zelda games, all for Game Boy Color -- the three Oracle games, two games based on previous Zelda chapters (including a GBC port of Zelda I and likely followed by a GBC port of Zelda II: The Adventure of Link), and one last original game creation assumedly outside of the Oracle series. Plans were due to change, however...

In 2000, the 3-game concept became too much for the platform and the limitations of the password system used for the games, so the team scaled the project back to just two games and restructured the password system and storyline. Mystical Seed of Power became Oracle of Seasons and Mystical Seed of Courage became Oracle of Ages, and both were released in 2001. The third chapter, Mystical Seed of Wisdom, was never finished, and it is unknown how much of the game was ever completed or how much was re-created in future Zelda titles. Nintendo later turned its focus towards the Game Boy Advance, and while the GBA-exclusive The Legend of Zelda: The Minish Cap was likely a completely new game with no design work carried over from any prior GBC Zelda work, Minish Cap does have a sly tip of the hat to the Oracle series (and the lost third chapter) in its Hyrule Town and in the appearance of Din, Nayru and poor Farore.