One Piece - Big Secret Treasure of the Seven Phantom Islands is an RPG game for Game Boy Advance, based on the animated television show One Piece. This game was released only in Japan in November 15, 2002 by Banpresto.
Luffy and his crew are sailing when a storm hits. The storm destroys the ship, and the crew members are scattered across an island, away from each other. Luckily, Luffy finds a bird who acts as a guide for the crew so they can reach each other. They eventually encounter the Simon Pirates. In various RPG battles, the Straw Hat Pirates eventually managed to defeat the entire Simon Pirates and leave the island.
- Simon Pirates
The gameplay plays like a traditional RPG. Luffy and his crew wander around the island looking for the other crew members. The player can choose three head characters for battle, but they may interchange characters in the field. The characters can use their special abilities to stun enemies and activate objects in the field.
Battles take place on a grid battle-field. The player can choose three head characters for battle. They can attack the opponent, or hit obstacles on the battlefield to hurt the enemy. The battle system also use a timed hit system, where pressing the A button when the attack hits causes extra damage, or a combo move to start. The maximum number of combo hits is 4.