2. collect ALL 7 dragonballs in extra mode.
whenever you see a tile with a charictor's face (from the game) collect it, and if you finish the game, you can play as that charictor (e.g., Oolong (as a bat/rocket), mini floting camera thing(has gun) and most of the boss's!
to get king piccollo, complete the game (goku & krillin) get the dragonballs (extra mode) and go to the "Small fry" mini-game. piccolo's tile will be randomly dropped by one of the baddies, once you have piccolo, go to "one-on-one" and go to suvival mode,beat survival mode with piccolo, and beat cyborg tao at the end to unlock him ion one-on-one mode!