Shoot Paintballs:
At the main menu press Up, Down, Left, Right, White, Up, Up. To shoot the paintballs press up on the D-Pad.
Mini Cars:
At the main menu press Up, Down, Left, Right, White, Down, Up.
Hardcore Realism Mode:
At the main menu, press Up, Down, Left, Right, White, Up, Down. Alternately, get a 100 point rating on a track to unlock the hardcore realism mode option for that track.
High Suspension:
At the main menu, press Up, Down, Left, Right, White, Left, Right.
Wire Frame Cars:
At the main menu, press Up, Down, Left, Right, White, Right, Left.
View Credits:
At the main menu, press Up, Down, Left, Right, White, Left, Left.