Developed by Capcom, The Legend of Zelda Oracle of Ages and Seasons were two special games which were unlike anything Zelda fans had seen before. Released in 2001 for the Game Boy Color, both games were developed side by side, and could actually be connected with a code you received from completing the game. Either game could be played as the "first" game in the series (although many fans do consider Seasons to be first, which is also the non canon manga chose as the starting point), and once you finished it a could would be unlocked to use in the next game. Once you started up the next game using that code, some minor changes would be made to reflect your choices in the original, you would start the game with an extra heart, and you would also unlock the ability to fight the game's true final boss. Although each game does in fact share the same "true" ending, the games themselves are completely different.
Each game takes place in its own unique world, they each tell their own story, and each one has unique gameplay as well. Oracle of Seasons is the gameplay/exploration based game with an item that allows you to change the game world's season. For example, while during the summer the beach will be a warm place for you to visit, in the winter it will be completely frozen over which will allow you to cross to the other side. There are also some animal helpers to help you progress through the game, and each one will change up the gameplay. Thanks to them there is a lot of different gameplay styles for you to experience, and it helps keep the game fresh and exciting.
If you are the type of person who loves exploration, and loves different styles of gameplay, Oracle of Seasons would be the perfect place to start.
Much like the Dark World from Link to the Past, the future world in Ages is a dark and shadowy place where everything has changed. This world is 400 years in the future, and during that time the world has evolved into something new. This world is filled with even more challenges for Link to face, and is designed specifically to test your skills as a player in every way.
Although each game in the Oracle series is designed to focus on a different aspect of the series, and appeal to different groups of fans, both games are a part of a set, and are best when played together. If you want to get the full experience out of the series, you really should pick up both as soon as possible. From there it is up to you to decide which game you want to play first. Personally, my favorite is Seasons, and I plan on picking it up the moment it goes up for download!