More points and Class B:
Earn a metal on each level in Class C, also if you want to unlock better weapons.

More points and Class A:
Earn a metal on each level in Class B, also if you want to unlock better weapons.

Unlimited points and Class AA:
Earn a metal on each level in Class A, also if you want to unlock better weapons.

                             Game Shark Codes

     1 Lap to Race -
          d022ad050001 
          8022ad050003 
     No Laps to Race -
          d022ad050000 
          8022ad050003