Zelda II: The Adventure of Link

Follow the steps below:

1. Save the game after completing the game once.
2. Use this character to complete a castle.
3. Press Start on controller one, then hold: Up + A on controller two.
4. Save the game and immediately begin game play with a new character. The new character's experience points will rapidly increase after starting.

To pass through locked doors without a key, simply turn yourself into a fairy (with the Fairy spell) and float on through.

At any time in the game press Start on Controller 1. Then on Controller 2 press Up and A to bring up the "Continue, Save, Retry" screen. Use this if you are stuck in a screen with no way out, and no way to lose a life. You can use this code to save your game (so you don't lose the items you have picked up), and start over from the starting screen.

To save without dying, try the cheat below. Press start on Controller one and on controller two press: Up and Start
If entered correctly a save screen will pop up. You have the choice to either Save or Continue.

To discover the art of the upward attack, go to Darunia and use the Jump spell to leap up to the house with a chimney. Drop down this and go right to find a knowledgeable warrior. The downward attack is found in Mido. Use the Jump spell to reach the open door at the top of the church, and go through to find a teacher.