Unlockables in the Legend of Zelda A Link to the Past:
Sword Beam (Four Swords) - Play LttP and get the Master Sword, then save game.

Unlock the level 'Palace of the Four Swords' in Single Player mode:
In order to unlock this level, you must beat both A Link to the Past and The Four Swords. Then get 20 Rupees, and go into the hole in the Pyramid of Power. Give the creature 20 Rupees, and he will dissapear, allowing you to pass. Beat this level to get a neat secret ending.

Unlockables using Four Swords:
Riddle Quest - Collect 10 Triforce medals in Four Swords
Hurricane Blade - Complete the Riddle Quest
Golden Sword Icon - In Four Swords, collect all of the Hero Keys and beat Vaati in the hero's door

The Chickens Attack:
The Chickens found in Kakariko Village and other areas have a vendetta against you; that is, of course, if you attack them. Hit a chicken enough with your various weapons, whether it be sword, arrow, bomb, whatever, and the chickens will come from all directions to peck you!

Hopping Hare:
In the Light World, go south of Link's house into the swamp. There you will find a blue rabbit jumping up and down in the grass. When it jumps up, cut up the grass below it, then when it comes down, go over to it and touch it. It will give a random item, such as 1 to 300 rupees, or a fairy. This can only be done before you reach the Dark World for the first time.

Different Statues in Links house:
After you get all the statues from completing the riddles go into your house and select the magic powder. Sprinkle it on the statues and they will sparkle. Sprinkle magic powder on them again to get them in color. Sprinkle them one final time to get Bunny Link, boneless chicken, and Zelda as an old lady.

Picture of Mario:
Go to the Treasure chest shop in the dark world in the Village of Outcasts. In the very back of the house, a picture of mario is hanging on the wall.

Exploding head:
In the light world, go to where you recieved the flute. Go down one screen. To the right where there are two trees. Stand next to the top tree and use the Ether medalion. Walk away from the tree and ram into it with Pegasus Boots and a head like Blind in her human-ish form will fall down and explode as if it were a bomb.

Zelda: Link to the Past Secrets:
Riddle Quest:
Obtain ten medals in the Four Swords multiplayer mode, and you can start a riddle quest with the Lumberjack in Link to the Past. Complete the Riddle Quest to obtain the Hurricane Blade special move.

Four Swords Progress:
To earn Silver Keys, complete each level with a team score of 1000 or more Rupees, then beat Vaati for ending #1.
To earn Gold Keys, complete each level with a team score of 3000 or more Rupees, then beat Vaati for ending #2.
To earn Hero Keys, complete each level with a team score of 5000 or more Rupees, then beat Vaati for ending #3.

How To Buy A Golden Bee:
Go to the cave with the Ice Rod, and go into the non-secret entrance, not the one leading to the Ice Rod. Dash into the statue at the end of the passage, and a Golden Bee will pop out. Catch it, and take it to the guy who refuses to sell you the Golden Bees. He will say that they are not as rare as he thought they were and will begin selling Golden Bees.

Easy Money:
After you've gotten the Power gloves go to the desert area in the game. Once there find the man thats sitting next to his sign. Go a little bit south and to the left where you should find two large rocks. Lift up the rock below the top one and a secret area will be opened. Once inside you'll notice a thief and 10 different pots that each hold a blue rupee, break open each pot and take all the money. You'll be able to do this as much as you please because the blue rupees come back every time you leave and reenter the area. It should only take a few minutes to get the maximum amount of rupees.

Free potion:
Once you've gotten the super bomb and already blew up the wall blocking the dark worlds fairy go inside and make sure you have at least one empty bottle with you. Go up to the Mysterious pond and it will ask you to throw something in. Scroll through your items until you come across an empty bottle, then throw it in the water. The Fairy will come out and ask you if you droped it. Answer yes and the fairy will say she likes such an honest person and will fill your bottle with green potion. You can do this as many times as you want.

Get the red shield before entering the dark world or paying 500 rupees:
After you get the Zora flippers, find the big waterfall in the light world. It should be near the area where you got the flippers. Once you see the waterfall walk right into it and you'll be able to go inside of it. Once your inside you'll see a pond and it will ask you to throw something in. Choose to throw your small shield in and a fairy will ask if it is yours. Answer "YES" and she'll give you a red shield.

Save the Fish:
When you are in the light world, go to the dungeon where you get the Ice Rod. To the left, you will see a little fish flopping around. If you catch it with the right button, you can go up one screen and throw it into the water. It will thank you with 20 ruppees.

Holding Nothing:
On any part of the Light World Death Mountain that is on top of the mountain (level with the Tower of Hera, or Mountain Tower) freeze one of the tekktites (those blue or red spidery jumping things) with the ice rod (the Ether Medallion will just kill it) and pick it up using the power glove. not jump off the edge of the mountain that leads to the ground level. The tekktie will suddenly disappear and when you land on the ground you will be holding thin air and you will walk at normal speed with nothing weighing you down. The only problem is, you can't use any items, including your sword, shield or pegasus boots, and you cant throw away the air that you're holding. The only way you can stop this is by entering a cave or by getting hurt. you can also pick up a green stone and do the same thing, but I can't guarantee it will work. Sometimes you may have to repeat the trick several times in order for the item you're holding to disappear. You can also do this in the Dark World Death Mountain where you enter the portal near Spectacle Rock. Pick up a flower, and jump off the cliff. In the Dark World it doesn't work that much, but if you try again it will work.

Walking on Water:
Call up the Flute Duck and fly to point 7 on the map, which is the light world watergate. go up one screen to the place where the water portal is. now go up to the top right corner of the screen in the shallow water. call the flute duck again but this time before it comes aim a correctly timed pegasus charge at your left side. if you time it right, the duck will pick you up when your sword is sticking out while you're dashing. When you enter the map screen, press B to cancel and the duck will put you back down on the ground. Here you will start walking funny and when you touch a solid surface, you will bounce off of it. now go up to the right-most green totem statue so you're facing up. walk into it and bounce off into the deep water. (if you just go directly into the water the trick won't work) Swim towards the water portal and get transported to that place east of the graveyard. If done correctly, you should be standing on the water instead of swimming. Here you can walk around any screen you like and still be walking, but do NOT jump onto one of those green platforms or the trick will stop immediately. And also, it is okay to use the Pegasus Boots, but if you crash into something, you will start swimming again. and if you call up the Flute Duck and press B to cancel the map selection, you'll be swimming.

Change color of Agahnim's skin/clothes:
During the Light World fight with Agahnim, he turns into a shadow, and moves around like that. If you bring up the map exactly when he is turning from shadow to real form, his colors will be really distorted, or he will look transparent, just like the 2 fake ones during the second fight. If you keep doing it, his colors will keep changing.