Sorry that was not clear. I really should stop writing things before I fall asleep.
I thought it was a real/non cheat hardware activated thing. I was just curious as to how you found it and assuming you did not sit there pressing random buttons to find it then chances are you at least observed things in an emulator. Such a hack is not commonly done and is an interesting way of thinking about things as far as game logic goes-- it is not really anything you encounter in text hacking, in graphics hacking, in level hacking, in music hacking or even in remapping controls.
If you did not use an emulator's nice memory viewing and did brute force it I imagined you instead saw that the devs/publisher have a history of such codes, that said menus were present in other regions/platforms or something similar.