How can I get to this secret world in SMB3

[Jabra]

additional world:

http://www.youtube.com/watch?v=40dwVLjnTpE&feature=related

[133MHz]

You can't, it's a hacked ROM where every unused stage in the game has been made easily accessible through a custom crafted world map. As far as I remember you can access some of the unused levels directly using Game Genie codes, but aside from that in real hardware your only options are a flashcart or a reproduction.

[satoshi_matrix]

Even still, this is great Powerpak fare. Anyone have a link to the rom for this specific hack?

[Xious]

It should be on Romhacking.net.