Secret clue:
While on the Mount Wannnahockaloogie level, look for an old brown sign. Dart behind the sign to score an important clue.

Cheats:
Enter these codes on the title screen:

Stage Select - TRIANGLE, TRIANGLE, TRIANGLE, SQUARE, SQUARE, CIRCLE, SQUARE, TRIANGLE, CIRCLE, SQUARE, TRIANGLE, SQUARE, TRIANGLE, SQUARE, TRIANGLE, CIRCLE, TRIANGLE, TRIANGLE.

God Mode - TRIANGLE, SQAURE, SQUARE, CIRCLE, CIRCLE, CIRCLE, TRIANGLE, TRIANGLE, SQUARE, SQUARE, SQUARE, CIRCLE, CIRCLE, CIRCLE, CIRCLE, SQUARE, TRIANGLE, CIRCEL, CIRCLE, CIRCLE, SQUARE, CIRCLE, TRIANGLE, CIRCLE, CIRCLE, SQUARE, CIRCLE, CIRCLE, TRIANGLE, CIRCLE, SQUARE, CIRCLE, CIRCLE, CIRCLE, TRIANGLE. (This cheat is toggled in the in-game options).

View Credits - TRIANGLE, SQUARE, CIRCLE, TRIANGLE, TRIANGLE, SQUARE, CIRCLE, TRIANGLE, SQUARE, CIRCLE, TRIANGLE, SQUARE, SQUARE, CIRCLE, TRIANGLE, SQUARE, CIRCLE, TRIANGLE, SQUARE, CIRCLE, CIRCLE, TRAINGLE, SQUARE, CIRCLE.

Play Secret Level - TRIANGLE, SQUARE, CIRCLE, CIRCLE, SQUARE, TRIANGLE, SQUARE, CIRCLE, CIRCLE, SQUARE, TRIANGLE, TRIANGLE, SQUARE, CIRCLE, CIRCLE, SQUARE, TRIANGLE, TRIANGLE, CIRCLE, SQUARE, TRIANGLE, SQUARE, CIRCLE, CIRCLE, SQUARE, TRIANGLE.