The original NES Metroid game also had a password, but just used letters and numbers IIRC. I remember taking a password for one of the games I was playing and

The original NES Metroid game also had a password, but just used letters and numbers IIRC. I remember taking a password for one of the games I was playing and incrementing it to find more valid passwords. Most of them took me back to the beginning of the game without any upgrades, but some of them put me in significantly later stages of the game without any upgrades.