Unlockables

Elemental Arrows

Fire Arrow Shoot the sun after the Water Temple
Ice Arrow Complete the Gerudo Training Ground
Light Arrow Beat all the temples, then talk to Shiek

Get a cow inside your tree house - Complete the task listed to have a cow put in your tree house.

Cow in tree house. After beating the race at Lon Lon ranch for Epona, race again and get the best time (49 seconds or below) to unlock a cow for your tree house.

Skulltulas Unlockable - To get this unlockable items, you must kill the number of Skulltulas Spiders that is required. After you kill the skulltulas spiders, collect the tokens and then go to the Skulltula House in Kakariko Village to get your prize.

Adult Wallet 10 Skulltula Tokens
Bombchus 40 Skulltula Tokens
Giant's Wallet 30 Skulltula Tokens
Huge Rupee 100 Skulltula Tokens
Piece of Heart 50 Skulltula Tokens
Stone of Agony 20 Skulltula Tokens