Classic NES Series - Zelda II - Platform: Gameboy Advance

Bypass forced encounters:
-------------------------
You can bypass a forced encounter if you enter the tile while it's being occupied 
by a random battle monster. Instead of fighting through the forced encounter you 
will fight a random battle. After the battle, you can simply step off the tile 
and continue.

Stay alive after a fatal hit:
-----------------------------
If you fall off the side of the screen when you get hit, you won't die, even if 
your HP is at 0. Stand very close to the edge of the screen, and attack from there. 
You can use this to level up without the risk of losing your EXP to a gameover. 
Especially at screens with jumping fish.

Unlock Fairy:
-------------
Find the Water of Life behind a boulder in the swamp, take it to Mido.

Unlock Fire:
------------
Examine the fountain in Nabooru then talk to the thirsty woman.

Unlock Jump:
------------
Find the Trophy north of Zelda and take it to Ruto.

Unlock Life:
------------
Find a mirror in an empty house in Saria and take it next door.

Unlock Reflect:
---------------
Find the child in the origin of the river in the maze and take him to Darunia.

Unlock Shield:
--------------
Talk to the old man in Rauru.

Unlock Spell:
-------------
Talk to the old man in Kasuto (you must hammer a tree in the woods farthest to the east).

Unlock Thunder:
---------------
Once you have everything else, talk to the man in the old ghost town of Kasuto