Invincibility: Press Start to pause game play, then press Left,
Right, Left, Right, Up(2), Down(2),
Left, Right, Left, Right, Up.
Information in this section was contributed by Arprad.
Super speed: Press Start to pause game play, then press Left(3),
Right(3), Up, Down.
Information in this section was contributed by Arprad.
Hard difficulty: Successfully complete the game, then start another
game with the cleared save file.
Level select: Collect all sixteen Bat symbols when playing under
the hard difficulty setting.
