Enter the options menu and select the ''Special Magic'' option. Begin game play and Hold A when the music for the Bosses on levels 1 to 4 begins to play. Defeat the Boss while holding A. Release the button when the screen turns black and your character is transported to the bonus level. Do not press any buttons or move the D-pad. When the next level begins, player one will cast a spell that will increase the magic points to 255. Note: Do not use more magic points that what your character normally is allowed to use. Doing so will freeze the game.
While the opening screen scrolls, simultaneously hold down a, b, c and start. Still holding A, realease b and c and press them again. This will bring you to the options screen. Still holding a, let go of the other two, pick 'exit,' and press b and c once more. You'll be back at the main menu. Still holding a, release b and c and hit them again to choose the number of players. Keep all the buttons down and press start. Release only start, select your character, then still holding down a, b and c, press up and hit start. You can now select the level you want to play.
With the cursor go to ''options'' sign.
Now press & hold A+B+C.
In the options screen relase only B & C
Now configure game if you want.
From now on ever use B to confirm successive selections,
until the warrior selection.
For the 8 credits, the cheat is identical, but you must relase only A and use START to confirm successive selections.