Fight as Boro:
Complete the game under the easy difficulty setting.

Fight as the Joker:
Complete the game to earn a star. Select "Survival" mode. Defeat
all one hundred characters. The Joker will be available on the
character selection screen.

Fight as the Master:
Complete the game to earn a star. Select "Master Challenge" mode
and defeat all opponents. The Master will be available on the
character selection screen.

Fight as Robert:
Complete the game to earn a star. Select "Fastest" mode. Defeat
all fighters in less then one minute. Robert the robot will be
available on the character selection screen.

Fight as Ushi:
Complete the game to earn a star. Select "Rodeo" mode. Remain
undefeated for at least one minute. Ushi the cow will be available
on the character selection screen in two choices of colors.

Winning poses:
Rapidly tap A or B after defeating your opponent.

View gained skill:
Press C-LEFT, C-RIGHT, C-UP, or C-DOWN before selecting a character.