Secret Room 
      At the end of the game after you past turtle rock, go to the light world
      and save your game, then get ready to run. Dash out of the sancuary,
      dash down then west one screen. Dash down another screen then dash
      east. Dash around the castle and into the secret entrance and you will
      be in a secret room. Go as fast as you can and avoid all the knights
      because it won't work if you're too slow.