Big head mode:
At the main menu, press Left + Circle, Left + Triangle, Left + Square,
Left + X. If you entered the code correctly, you will hear a sound.
Regain energy:
When given a choice to hit the heavy or speed bag between fights, hold
L1 + L2 + R1 + R2 to regain two to eight points of energy, depending
on how long the buttons are held.
Taunt opponent:
During a match, press R1 + R2 + X.