More and more development builds and assets from classic Nintendo video games have found their way to the Internet in the past few years, but it's still a nice surprise to see in-progress versions of beloved favorites pop up.  Today's game under the magnifying glass is 1991's Super Mario World for the Super NES, as Forest of Illusion has acquired and documented an October 1990 localization prototype used to prepare the game for its North American release.  This version contains a different title screen logo, different fonts, a few script changes, a slew of enabled debugging tools, and some other interesting changes.  Check out the video for the full set of documented differences. It's an interesting peek behind the curtain.