Snowboard Kids 2 (N64)

All Characters, Boards and Levels:
At the Title screen press Z, B, C-Up, Down (D-pad), Left (Stick), Right (Stick), Up (D-Pad), R, Z, A

Expert Mode:
Complete Story Mode to access Expert mode.

Bonus Characters:

Mr. Penguin	Defeat him in Training Mode.
Damien	Complete the entire Story Mode.
Mr. Dog	Complete the Shoot Cross test.
Panda	In battle mode, select Mr. Dog wearing his space suit.

Unlocking the Ice Snowboard:
Beat the Snowman Boss track on Expert Mode. This board is slippery and hard to control.