Sega Master System / Mark III / Game Gear
During the Sega logo, press five times. A sound will confirm the code and the message
Excellent will appears at the title screen.
To rename the Cypress's prince, confirm the name of the main character with +. To rename other characters of the game, confirm the name of the Cypress's prince with +.
During the fifth battle, search the well next to the house to find the ticket. This will give you access to see the Mime Show at the end of the game.
First, finish the game. Now, when you start or restart a game, hold + when the narrator says the last words to access the Sound Test.
To enable the sound test without actually having to finish the game, edit save memory location 1B0F and set it to 3. You will be able to access the sound test as if you had completed the game normally.