Extra power-ups: 
Collect a power-up, then leave that location and 
return. The power-up will reappear and may be 
collected again (the maximum number of nitros 
that may be collected is five).

Lose the police:
When chased by the police, you can cut them off
by hitting them on the back when they try to cut
you off.

Play any Episode/Scene: 
Complete the game, then save to a memory card.
Load the saved game from the options/memory 
card screen to chose any episode and scene. 
Chose quit to the main menu and save the game
again at the options/memory card screen.