To unlock the hidden second quest, of The Legend of Zelda, you must enter your name as “Zelda” at the title screen before starting the game.
When in a dungeon I suggest killing all enemies except for one in each room that you go through. This way, if you have to return to that room for any particular reason, that lone enemy will be all that remains. If you kill all of the monsters, then they will all respawn when you leave and come back.
Quickly Kill Ghoma
To kill Ghoma extremely quickly, you must equip your bow and arrow before you enter the boss chamber. Then as soon as you enter the boss room. fire an arrow. It will hit Ghoma in the eye and kill her with one hit.
Save a Key on Dungeon One
In the first room of this dungeon is a locked door to the North. If you enter the dungeon and then turn around and leave right away, the door will be unlocked when you go back in. This is a great way to save yourself some time and a key.