Ninja Land course:
Earn a gold cup on the "Silver Mountain" bonus course.

Silver Mountain course:
Earn a gold cup on the "Quicksand Valley" bonus course. This will also enable a special ending sequence will all characters.

Play as Shinobin:
Earn a gold cup on the "Ninja Land" bonus course.

All snowboards, characters, and courses:
Press Analog-stick Down, Analog-stick Up, Down, Up, C-Down, C-Up, L, R, Z, Left, C-right, Analog-stick Up, B, Right, C-Left, Start on the starting screen. Nancy will laugh to confirm entry. Or, press Analog-stick Up, Analog-stick Down, Down, Up, C-Down, C-Up, L, R, Z, Left, C-right, Analog-stick Up, B, Right, C-Left, Start at the starting screen.

Slash's moves:
Banzai bash: Analog-stick Left, Analog-Stick Right
Spin: Analog-stick Up, Analog-stick Down, Analog-stick Up
Dynamite: Analog-stick Right, Analog-stick Left, Analog-stick Right, Analog-stick Left