LEVEL SELECT
At the first title screen, press A, B, Right, Left and one of the following combinations:
Level 2: Up + B.
Level 3: Up + A + B.
Level 4: Up + Select.
Level 5: Up + A + Select.
Level 6: Up + B + Select.
Level 7: Up + A + B + Select.
Level 8: Up + Right.
Level 9: Up + Right + A.
Level 10: Up + Right + B.
Level 11: Up + Right + A + B.
Level 12: Up + Right + Select.