One Piece - Big Secret Treasure of the Seven Phantom Islands

One Piece - Nanatsu Shima no Daihihou is a RPG game for Gameboy Advance, based on the animated television show One Piece. This game was released only in Japan.

Story
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.

Playable Characters
Monkey D. Luffy

Nami (One Piece)

Roronoa Zoro

Usopp

Sanji

Tony Tony Chopper

Gameplay
Exploring

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.

Battling

Battles take place on a grid battle-field. The player can choose three head characters for battle. You 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 will start. The maximum number of combo hits is 4.