Ogura, the villain from Densetsu no Stafi, is furious at his defeat at the hands of Stafi, the starfish prince. After escaping from his prison, he kidnaps the queen, and whisks her away to a far off land. Stafi must travel across the kingdom to rescue his mother and defeat Ogura once again.
Densetsu no Stafi 2 is the sequel to the original Game Boy Advance game. As Stafi, you can swim around freely in the water, as well as run, jump and later glide in the air while out of water. You'll receive help from Kyorosuke the Clam, your mentor, as you play. Stafi's goal in each level is to find the treasure chest and grab it. However, access to each chest is usually blocked off until you complete a specific task for a character in the level, such as destroying a particular amount of enemies or finding certain items.
Once you make your way through all the levels in a world, you'll have to face a boss. It's you versus them - the first to lose five hit points will lose. Each boss can only be hit during a particular time or in a particular area. Once you beat the boss, it's onto the next world for more levels to beat and another boss to conquer.