Mike Tyson Heavyweight Boxing

When "Press Start" appears at the title screen, press:
Master code  - Square, Circle, L2, R2.
All created boxer items - L1, R1, X(x2), Triangle, X.
Random sized boxers - Square, Left, Up, Triangle.
Big heads   - Square, Circle, Up, Down.
Small heads - Square, Circle, Down, Up.
View full credits - X, Triangle, Square, Circle.

 