Play as Crocodile: Successfully complete Event Battle as Robin.
Play as Orm: Successfully complete Event Battle as Chopper.
Play as Smoker: Successfully complete Event Battle as Zoro.
Play as Wiper: Successfully complete Event Battle as Luffy.

Play as Enel:
Unlock Smoker, Crocodile, Wiper, and Orm, then successfully complete Event 
Battle as Luffy or Wiper.

Play as Hina:
Unlock Enel, then successfully complete Event Battle as Usopp under the hard 
difficulty setting.

Play as Bon Clay:
Unlock Hina, then successfully complete Event Battle as Sanji under the hard 
difficulty setting.

Play as Ace:
Unlock Bon Clay and the third costumes for Luffy, Zorro, Nami, Usopp, Sanji, 
Chopper and Robin (by completing training mode with them), then successfully 
complete Event Battle as Smoker under the hard difficulty setting.

Play as Shanks:
Unlock Ace, complete Event Battle under the hard difficulty setting as Luffy, Zorro, 
Nami, Usopp, Sanji, Chopper and Robin, and unlock the Windmill Village and 
Marine HQ stages. Then, successfully complete Event Battle as Luffy under the 
hard difficulty setting. 

Alternate costumes:
Complete the following goals to unlock the corresponding costume for the 
indicated character.

Luffy's group's third costume: Successfully complete training mode as Luffy, Zorro, 
Nami, Usopp, Sanji, Chopper and Robin. 

Luffy's group's fourth costume: Win Grand Battle (three rounds, hard difficulty, 
unlimited time) with Luffy's group's third costume against any CPU player. Note: 
You must win all three rounds with a level 2 special. 

Shanks' third and fourth costumes: Unlock Luffy's third and fourth costumes, then 
successfully complete training mode as Shanks. 

Wiper's third costume: Unlock Luffy's and Shanks' third and fourth costumes, then 
successfully complete training mode as Wiper. 

Alternate commentary:
Successfully complete Event Battle under the normal difficulty setting as any 
character to unlock that person's voice as a commentator. 

Super Hard difficulty:
Successfully clear all moves for all sixteen characters in training mode.

Windmill Village stage:
Unlock Enel, then collect all 48 cards in Event Battle. 

Marine HQ stage:
Enter training mode and get your bomb catching over 51.