"The Legend of Zelda: Oracle of Ages is an action-adventure game developed by Flagship and published by Nintendo and the seventh and eighth installments in The Legend of Zelda video game series. They were released on February 27, 2001 in Japan, May 14, 2001 in North America, and October 5, 2001 in Europe for the Nintendo Game Boy Color. The game features a brighter color palette when played on a Nintendo Game Boy Advance in order to make up for the darkness of the screen, and a special shop is also made available.
After experimenting with porting the original The Legend of Zelda to the Game Boy Color, Yoshiki Okamoto's Flagship team began developing three interconnected Zelda games that could be played in any order. The complexity of this system led the team to cancel one game; the remaining two were adapted into Oracle of Seasons and Oracle of Ages. The two games, released simultaneously, interact via a Game Link Cable and a password system.
In Ages, the Triforce transports Link to Labrynna, where Nayru is kidnapped by Veran. The main plot is revealed once the player completes both games. The player controls Link from an overhead perspective, using basic controls copied from The Legend of Zelda: Link's Awakening for the Game Boy. Link is armed with a sword and shield as well as a variety of secondary weapons and items for battling enemies and solving puzzles. The central items of the games are the Rod of Seasons, which manipulates the seasons of Holodrum, and the Harp of Ages, which allows Link to travel through time in Labrynna. Link gathers the eight Essences of Nature and the eight Essences of Time, hidden in dungeons and guarded by bosses, to obtain the power to penetrate Onox's castle and Veran's tower."
Source: Wikipedia, "The_Legend_of_Zelda:_Oracle_of_Seasons_and_Oracle_of_Ages," available under the CC-BY-SA License.