Milon's Secret Castle/Secrets and codes

Fast Fire Testing
At title screen, there is a number "0" at the top. If the player presses a certain button many times in a short period, the number will tell how fast the input is. This number will also become the initial number of notes in Bonus Stage.

Continue your game (Famicom / NES)
In order to continue your game, you must obtain the first crystal from the boss on the first floor. Once you possess this crystal, you can continue your game after you lose all of your health by returning to the title screen, holding and pressing.

Instruments in Bonus Stage
As Milon collects more Music Boxes, the people in the Bonus Stage will appear with more instruments, making the music more complete.

Extra Ending Message (Famicom / NES)
Beat the game 8 times in a row to get an extra ending message. Every new game will increase enemy durability by a bit. If succeeded, this message will appear with full music of the Bonus Stage.