Cheat mode:
Hold Run, press Select six times, then release Run at the title screen. Then, hold I + II + Up/Left and press Run. Press Select + Run to choose different options. Press Run, Select to reset the options.

Princess mode:
Hold I for approximately ten seconds at the title screen. A message will appear on the sign to confirm correct code entry.

Continue:
Hold I and press Run while falling to continue game play from the last game location.