There is a zero world that was left in the game, probably after testing stages. However, it may be impossible to get to it through normal means. You can supposedly get to the level with a Game Genie (code: YSAOPE + YEAOZA). Also, if you use the emulator Nestopia, you can get to the level through doing a "Hard Reset" a couple of times. But, how do you emulate this hard reset in real life? Some people have had this level come up when they turn on their games for no apparent reason. The main screen looks normal, except it says (0-1) at the top. The level is a water level, with water inside of water (the image for the tops of water is in the actual water) and the level is sort of maze-like: if you go the wrong path, you get to a dead end with no way out. To get through the level, stick to the bottom. Once you get to the end, you'll find a Bowser area underwater, with no Bowser. Grab the axe and you'll walk forward and the words that go something like,"Mario, thank you! But our Princess is in another castle!" will appear with no Toad. Then press B and you'll get out of the level. Strange, eh? One very interesting observation made by Clark Beyer - the level appears to be a castle, just underwater! The walls may have been positioned like a castle's walls, and the water under the water may have been lava. Strange, eh?
Submitted by: kornyhatemachine