Enter the following codes during regular gameplay using the second controller (use the D-Pad for directions):
Bunch of Cash! - B, Z, Z, B, Up, Bottom-C, Z, Start.
Super Blurry Mode - B, Left, Up, Right, Right, Right, A, Start, Start, Z, Right, A, Up, Z, Bottom-C, Start.
Top Down View - Up, Up, Up, A, Left, A, A, A.
Snowboard - Enter BUCKYB as your name.
Milk Truck - Enter MOOOOO as your name.