Mega Man 2 had a similar password concept, but has less state to calculate: https://retromaggedon.com/index.php/mega-man-2-nes-passwords/ https://retromaggedon.

Mega Man 2 had a similar password concept, but has less state to calculate: https://retromaggedon.com/index.php/mega-man-2-nes-passwords/ https://retromaggedon.com/index.php/mega-man-2-nes-passwords... I recall seeing codes in gaming magazines at the time, it was pretty neat being able to "send" this state over the mail.