Dobutsu No Mori

Super Mario Bros was only legitimately obtainable in Doubutsu no Mori+, where a Nintendo GameCube Memory Card with the item data on it was sent to 30 winners of a sweepstakes in Weekly Famitsu Vol. 678 in December 2001. The item is otherwise only obtainable with a secret code that is specific to the player's name and their town's name; however, since Nintendo never offered a code generator which generated a Super Mario Bros code, it is only possible to obtain through the use of a third-party code generator.