Enter MUSIC/ON as a name.
Enter FIRESEAL as a name to start at Dragon's Heaven with a strong army.
Enter GOTOHELL as a name. Note: This affects both sides of the game.
To find the four Chaos Gates, go to the place where in a town someone will say "I saw a Flying unit go.... (east.)". Go there. You will unlock four hidden areas (the three Sky Islands) to recruit the three High Knights, but you will need the sword Brunhild.