Unlock All Parks:
While playing, press Square, Circle, Triangle, Square, Circle, Triangle, Square.
Unlock All Rides:
While playing, press Square, Circle, Triangle, Square, Circle, Triangle, Triangle.
Get $50.000:
While playing, press Square, Circle, Triangle, Square, Circle, Triangle, X.
Complete Mission:
While playing, press Square, Circle, Triangle, Square, Circle, Triangle, Circle. Then press Square to complete the mission.