Choose "Enter Password" at the Options menu and input one of the following passcodes to gain access to all of the game's stages, including the endings:
Easy Difficulty Level:

X,O,X,O,X,Triangle

Medium Difficulty Level:

X,X,Triangle,O,X,Triangle

Hard Difficulty Level:

Triangle,Square,Square,Square,X,Triangle

Choose "Enter Password" at the Options menu and input one of the following passcodes to gain access to all of the game's stages, including the endings:
Easy Difficulty Level:

X,O,X,O,X,Triangle

Medium Difficulty Level:

X,X,Triangle,O,X,Triangle

Hard Difficulty Level:

Triangle,Square,Square,Square,X,Triangle

level 1: (NONE)
level 2: X, Triangle, X, O, O, O
level 3: Triangle, Square, X, O, O, X
level 4: Triangle, O, X, O, O, Triangle
level 5: Triangle, X, X, O, Square, Square
level 6: Triangle, Triangle, X, O, Square, O
level 7: Square, Square, X, O, Square, X
level 8: Square, O, X, O, Square, Triangle
level 9: Square, X, X, O, Triangle, Square
level 10: Square, Triangle, X, O, Triangle, O
level 11: O, Square, X, O, Triangle, X
level 12: O, O, X, O, Triangle, Triangle
level 13: O, O, Triangle, X, X, Square
level 14: O, Triangle, X, O, X, O
level 15: X, Square, X, O, X, X
level 16: X, O, X, O, X, Triangle