Overview: In addition to the GBA game, Bandai also made a fighting game for PS2 and GameCube, bringing together characters from most of the One Piece saga for one hell of a rumble.
Story: It's a fighting game, so there's really no story.
Graphics: Not too shabby. The characters seem almost "chibified", as they look kinda super-deformed. But I still like it.
Sound: Here's where the game loses points. First off, the music is a little bland. It wasn't horrible, but nothing really jumped out at me either. But the worst of it is that 4-Kid's posse of untalented hacks they call "voice actors" are doing all the voice-overs. Granted, some voices sounded okay, like Zoro's and Smoker's. But many of those voices are just putrid (the other Straw Hats can't act if their lives depended on it).
Gameplay: There are plenty of different modes to play in. Story Battle, or Event Mode, is a series of battles you fight using a particular character; this is where you'll unlock the hidden characters. Then there's the Usopp Pirate's challange, where you play a set of Mini-Games. Then Grand Tourny, a no-holds-barred fight to the finish, and Grand Battle a vs. mode against a friend or the computer. There's plenty of unlockable artwork and other stuff to be found in the different modes as well.
Challege: If you want to unlock everything, you'll have to get good enough to survive Event Mode's 'Hard' and 'Very Hard' modes. The Usopp Pirate games are challenging as well. Like the GBA game, it's a tough game, but not over-the-top hard.
Final Rating: 9.5/10 The only big drawback is the dub voices, with no option to switch to the Japanese voices. And I hear Enel, Aokiji, and Foxy were taken out of the US game because the dub didn't get that far, along with Robin's bonus costumes for the same reason. Nonetheless, it's still a great game for One Piece fans that's worth checking out.