If you play a SMB rom using NESten, you can use the cheating capabilities to play strange, new levels. Here's how to do it:
1. During play, input addresses $075F and $0760. The first address is the current world you are in, while the second is the level.
2. Input one less the number(s) of the world/level you wish to go to (ex: $075F=4 and $0760=2 will take you to world 3-1) and set the addresses for those numbers.
3. Have Mario die, and you should be in the desired level. The display on your screen might not reflect the current level, but it's right.
If you set $075F to 8, you'll end up in world 9. And if you set it to 9, you'll be in world A. Here's the levels I've written down so far:
9-1 Swimming version of 6-2. Freezes after 6th pipe.
9-2 Swimming version of 1-4. Game will restart in Expert mode.
9-3 Secret underwater zone of 5-2. Continus loop.
9-4 Bottomless pit
A-1 Swimming version of 3-1 sky bonus. Continus loop.
A-2 World 8-1
A-3 Bottomless pit II
A-4 Swimming verson of 1-3
B-1 Underground version of 3-4. Game will restart in Expert mode.
B-2 Swimming version of 4-4.
B-3 Overworld version of 1-2. Continus loop.
B-4 Same as B-2
C-1 Same as 9-2. Will start after ? Block. Game will restart in world 3-1
C-2 Same as 9-3
C-3 Same as 9-4
There are a lot more I'm guessing, since NESten allows you to input up to 255. The minus world is $075F=35, and there are differences between the .NES and .FDS roms.
