I found a problem with the Game Genie code for leveling up after every battle in the original Final Fantasy. The code does work in the sense that you do level up after every battle. However if you try to enter the castle at the start of the game you can't proceed as there is a retaining wall blocking your every movement but back out of the castle. Also after you complete your first mission of saving the princess from Garland and returning to the castle you are trapped in the castle. After talking to anyone the dialog boxes don't disappear.