Crazy Super Mario Land 2: 6 Golden Coins Glitch

In Super Mario Land 2: 6 Golden Coins, if you exit a level while traveling through a pipe and then re-enter the level, you can fall through the floor into the game’s code, as represented by tiles from the game. If you touch the right tile, you can initiate the end of the game in as quick as 3 minutes 41 seconds!

(For more info on how this is possible, click the source link below the video and read the full description on YouTube.)