Fascinating trick in which one actually reprograms Super Mario World by just playing it to make it start playing the end credits upon triggering a crash:
The goal of this run is to trick the game into playing the credits in the first level. It works by using a glitch to allow yoshi to eat a chuck, which you cannot normally do. This executes improper code and usually crashes the game. The memory addresses read during the crash can be manipulated. By spawning a p-switch in a certain order and placing it at a pixel perfect position, as well as despawning two block break sprites at a mostly pixel-perfect height, the game reads the x/y position of the sprite slots as though they were code instead of executing random code and crashing. The shells at the start of the level are spawned in these sprite slots and placed at pixel perfect positions which, when read as code, call the credits.
A much shorter run, but without any explanation, is also available.