Test mode : hold START during machine boot.
Something not found in the manual to this game is that there exists a 'secret' mode of the game - if you set dip switch 7 of bank 2 to 'ON' you will get one life less than usual (2 instead of 3 or 5), but the life meter will start at 22 and not 12 or 14 which is the standard. This will make the game much more interesting.
Every time you die you loose every equipment you collected up to that point, unless you also have a 'K' Item in your inventory. If you have it, when you die you will only loose the 'K' but keep the rest of the items.
There is a secret level that can be reached collecting a magic key on the Ice, Hell or Sky world. Other may exists. This world is called 'World of Labyrinth'.
When you complete the 'World of labyrinth', you will meet an angel. Do NOT attack her, but wait until she drops an harp. If you collect it, it will work as a perpetual 'K' item, and you will never loose your items again when you die.
When you complete the 'World of labyrinth', you will be returned to the level following to the one you picked up the key on.