Unlock All Parks:
     While playing, press X, B, Y, X, B, Y, X.

Unlock All Rides:
     While playing, press X, B, Y, X, B, Y, Y.

Get $50.000:
     While playing, press X, B, Y, X, B, Y, A.

Complete Mission:
     While  playing,  press  X,  B,  Y,  X,  B,  Y, B. Then press X to
complete the mission.