The Japanese Famicom didn't have a CIC lockout chip, which let you hotswap games and then soft reset, preserving all of the RAM (a power cycle doesn't decay all RAM instantly, but it deteriorates rapidly.)
People would play Mario, then swap in certain games (mostly Tennis), then swap back to Mario, and then try the trick where you hold select or whatever to resume at the level you last died at.
Depending upon the contents of RAM based on what the other game wrote there, it would warp you to all of these corrupted worlds.
People would play Mario, then swap in certain games (mostly Tennis), then swap back to Mario, and then try the trick where you hold select or whatever to resume at the level you last died at.
Depending upon the contents of RAM based on what the other game wrote there, it would warp you to all of these corrupted worlds.