The Legend of Zelda: Oracle of Ages

The Legend of Zelda: Oracle of Ages (ゼルダの伝説 ふしぎの木の実 時空の章) is an action adventure game from Nintendo's famous The Legend of Zelda series. It was developed by Flagship and published by Nintendo in 2001 for the Game Boy Color.

It is commonly abbreviated OoA or tLoZ:OoA, although the grammatically correct abbreviations would be OA or LZ:OA.

Oracle of the Ages is so far the only game in the series to be released simultaneously with another title, Oracle of Seasons. It is also the only time two Zelda titles could interact with each other. This feature allows many hidden items, locations, antagonists, and secrets to be revealed, and causes the plots of both games to merge, continuing to a double ending.

Story
Called by the Triforce, Link travels to the shrine of the sacred relic. He is beckoned by the sacred triangles, and they transport him to a world known as Labrynna, which is in dire need of the legendary hero.