i dont know

well theirs 2 ways to unlock all caracters 1:you beat the game on story mode on all
difficultys 2:you get a game shark and enable the cheats

to unlock all the characters you also have to complete all the chalenge and arcade leages
as they to awwrd characters you will need to complete them with the best scores possible
just as you will need to complete all story mode levels on each dificulty