Golden Sun: The Lost Age is a Game Boy Advance video game. A sequel to Golden Sun, The Lost Age continued the story of various characters from the video game including Felix, Jenna, Sheba, and Piers. In the original game, Felix was among the villains. Isaac and the gang from the original do not make as much of a presence in this game as they did in the original. Interestingly, if the player completed the events in the original Golden Sun, they can transfer some of the data over to the new game, including the playable characters (Isaac, Garet, Ivan, and Mia). This can be done by inserting a password or by using a Game Boy Advance Link Cable.
In The Lost Age, all of the characters are called adepts (as the fours characters in Golden Sun were called). Adepts are able to use Psynergy and take control of the Djinn that are scattered across the game world. Djinn are given to characters, though can be traded. Trading Djinn is a key into exploiting the character's strengths, and doing so can ultimately change the difficulty of the game. Pairing Djinn with a certain character can also give them special powers that they previously were not in possession of.
Psynergy is used both while traveling and while in battle. While navigating the world, the player can use Psynergy to solve puzzles. New types of Psynergy is granted to the characters in three different ways: by giving the characters Djinn, by giving them items, and by leveling them up. While in battle, the Psynergy the player uses will effect the enemies in different ways, depending on that enemy's type.For example, using a Psynergy with water properties will prove especially effective against a fire based enemy. Other actions the player can perform in battle include using their weapon, summoning a monster and using Djinn. The player can summon a monster by placing a Djinn on standby, which means that while the user cannot use the Djinn, they will be given access to unheard of powers thanks to the monsters.