The following information was taken from the Atlus website when Lufia: The Ruins of Lore was released.
The militaristic nation of Gratze has suddenly launched attacks on its unsuspecting neighboring kingdoms. Under the command of Ragule, a self-serving foreigner who mysteriously worked his way into the King's graces, Gratze's forces are attempting to locate and reunite the body and spirit of a legendary beast that was sealed away long ago. Ragule secretly wants the beast's power for his own, so that he may rule over all humanity. He'll stop at nothing to reach this end, whether it be pillaging helpless villages or dismantling ancient ruins one stone at a time.
Meanwhile, Rubius, a priestess of Nazarre, journeys afar to gather the ancient stones said to be the key to the beast's whereabouts. During her travels, she encounters Eldin and his friends, Torma and Rami. These aspiring treasure hunters are quickly drawn into the historic sequence of events. Rubius reveals to them the purpose of Gratze's invasion, and the companions set out to thwart Ragule's plans and save the world from destruction. Their quest will take them across foreign lands, into the depths of ancient underground caves, and even backwards through time itself!
Control and manage up to 8 characters in your party. Dynamic battle system allows you to actively switch them in and out during battle sequences.
Capture various types of monsters to fight alongside you as loyal companions. Monsters can gain experience, learn new skills, and change into more powerful forms. You can even fuse with your monsters to overcome the toughest adversaries.
Choose from 11 distinct character classes, and take advantage of the job system to mold your characters as you see fit. Train them by accepting apprenticeships from a variety of skilled masters, including spellcasters, martial artists, thieves, and swordsmen. Gain experience and learn new spells and techniques as you prepare for the final battle.
Explore all 60 levels of the Ancient Cave to obtain rare and powerful treasures that you won't find anywhere else. Each time you enter the cave the mazes are randomly generated, creating a new adventure every time!
Link up to 4 GBA systems together to exchange monsters and explore the Ancient Cave with your friends.