That headline is <i>very</i> misleading.<p>The guy didn't just "rewrite" the game, he ported it to a completely different hardware!<p>The rewrite takes advantage of a separate CPU (the SA-1), so while the original was rendered entirely in software, his version is hardware accelerated. That hardly counts as a "rewrite" (which would imply that his code changes led to the speed-up), but an actual port to a different platform.<p>So it wasn't his code changes that are responsible for the performance increase, it's the use of additional dedicated hardware...
Oh hey it's Victor Viela. He's known in the Super Mario World ROM hacking community on a patch that adds SA-1 functionality to that game too, with some truly insane effects:<p><a href="https://www.smwcentral.net/?p=viewthread&t=104830" rel="nofollow">https://www.smwcentral.net/?p=viewthread&t=104830</a>
Seeing that game gives me some nostalgia. I remember playing it as a little boy. There was one in the corner of the local department store that got it’s fair share of quarters from me.<p>For as great as the SNES was, it’s kind of disappointing Nintendo out of such a poor quality port. Cool to see folks still working on these old games.