Completing the game unlocks the option of starting a new game in Hero Mode by over-writing your completed game save. In Hero Mode, hearts will deplete twice as fast, and hearts and heart flowers will not appear unless you carry a heart medal. Additionally, you will start the game with a fully powered up Skyward Strike attack and will remain with all of your collected insects and treasures from before. The Sheikah Stone will allow you full access to all of the hints since you will have already completed the game once. Finally, the boss rush challenge will also include the final boss as a foe.

Gratitude Crystals are earned through Gratitude Requests made by the townspeople. There are also several located in the sky. After finding some of them, bring them to Batreaux and she will reward you for certain amounts. Note: This is the only way to obtain larger wallets:

REWARD - NUMBER OF GRATITUDE CRYSTALS
The Medium Wallet (Holds 500 Rupees) - Find 5 Gratitude Crystals
Piece of Heart - Find 10 Gratitude Crystals
Big Wallet and Cursed Medal (Holds 1,000 Rupees) - Find 30 Gratitude Crystals
Gold Rupee - Find 40 Gratitude Crystals
Giant Wallet (Holds 5,000 Rupees) - Find 50 Gratitude Crystals
2 Gold Rupees - Find 70 Gratitude Crystals
Tycoon Wallet (Holds 9,000 Rupees) - Find 80 Gratitude Crystals

Earn the following rewards by winning the corresponding number of battles in the Thunder Dragon's Lightning Round:

REWARD - NUMBER OF BATTLES
100 Rupees - Win 3 battles
2,000 Rupees - Win 9 battles
20 Rupees - Win 1 battle
3 Rare Treasures - Win 10 battles
3,000 Rupees - Win 11 battles
300 Rupees - Win 5 battles
500 Rupees - Win 7 battles
9,900 Rupees - Win 12 battles
Hylian Shield (If your bag or storage is full, or you have already obtained the Hylian Shield, it is 1,000 Rupees) - Win 8 battles
Piece of Heart (Afterwards it's 200 Rupees) - Win 4 battles
Rare Treasure (Random) - Win 6 battles
Small Treasure (Random) - Win 2 battles

Sometimes in dungeons you can find small stools or chairs. Sitting on them and waiting a couple seconds will start to refill all of your hearts. You can do this anytime and as often as you want.

When you play your harp around a bunch of butterflies in certain areas of the game, a Goddess Wall sometimes appears nearby. Hold your sword up to the light, then draw various symbols on the wall in order to grab the related item. For a group of recovery hearts, draw a heart. For a bunch of rupees, draw a rupee. Drawing an arrow grants you arrows. Painting a circle gives you bombs. If you can manage to draw the Triforce, you'll get some fairies.

At the Waterfall Cave in Skyloft at Night, search for 3 Blessed Butterflies flying around and play your harp like you would to summon a Gossip Stone. The Moonlight Merchant will be summoned instead. He sells rare treasures at expensive prices but they're usually hard to find any other way.

ITEM - RUPEES
Blue Bird Feather - 200 Rupees
Dusk Relic - 100 Rupees
Evil Crystal - 100 Rupees
Goddess Plume - 200 Rupees
Golden Skull - 200 Rupees
Monster Horn - 100 Rupees

To make better potions, catch Bugs (with the Bug Net or Big Bug Net) found throughout the Overworld and bring them to the Potion Lady's husband in the Skyloft Bazaar. You'll need both a potion you bought from the Potion Lady and the right number bugs in order to receive upgraded potions:

POTIONS/RUPEES - INGREDIENTS
Air Potion+ (Upgraded from Air Potion) -- 20 Rupees - 2 Sky Stag Beetles, 2 Skyloft Mantises, 2 Lanayru Ants
Guardian Potion+ (Upgraded from Guardian Potion) -- 40 Rupees - 1 Faron Grasshopper, 2 Eldin Rollers, 3 Blessed Butterflies, 3 Starry Fireflies
Heart Potion+ (Upgraded from Heart Potion) -- 20 Rupees - 1 Woodland Rhino Beetle, 3 Blessed Butterflies, 1 Volcanic Ladybug
Heart Potion++ (Upgraded from Heart Potion+) -- 30 Rupees - 3 Deku Hornets, 3 Blessed Butterflies, 1 Sand Cicada, 1 Eldin Roller
Revitalizing Potion+ (Upgraded from Revitalizing Potion) -- 20 Rupees - 3 Deku Hornets, 2 Skyloft Mantises, 2 Woodland Rhino Beetles
Revitalizing Potion++ (Upgraded from Revitalizing Potion+) -- 30 Rupees - 3 Lanayru Ants, 2 Woodland Rhino Beetles, 1 Gerudo Dragonfly, 1 Sand Cicada
Stamina Potion+ (Upgraded from Stamina Potion) -- 20 Rupees - 3 Volcanic Ladybugs, 2 Sky Stag Beetles, 2 Gerudo Dragonflies, 1 Faron Grasshoppe

You can upgrade certain weapons and items with the necessary treasures. Random treasures are found all over the overworld, including from Treasure Chests in dungeons to defeating different types of monsters. To upgrade your equipment, talk the the owner of the Scrap Shop in Skyloft. Make sure you have the appropriate funds and the materials you need in order to upgrade:

GEAR/RUPEES - REQUIREMENTS
Banded Shield (Upgraded from Wooden Shield) -- 30 Rupees - 2 Amber Relics, 1 Monster Claw, 1 Jelly Blob
Big Bug Net (Upgraded from Bug Net) -- 100 Rupees - 3 Tumbleweeds, 2 Ancient Flowers, 1 Evil Crystal
Braced Shield (Upgraded from Banded Shield) -- 50 Rupees - 2 Monster Claws, 3 Amber Relics, 2 Tumbleweeds, 1 Ornament Skull
Divine Shield (Upgraded from Sacred Shield) -- 100 Rupees - 3 Ornament Skulls, 1 Dusk Relic, 2 Bird Feathers
Fortified Shield (Upgraded from Reinforced Shield) -- 100 Rupees - 3 Eldin Ores, 3 Monster Claws, 3 Tumbleweeds, 1 Blue Bird Feather
Goddess Shield (Upgraded from Divine Shield) -- 150 Rupees - 3 Monster Horns, 4 Dusk Relics, 3 Bird Feathers, 1 Blue Bird Feather
Iron Bow (Upgraded from Wooden Bow) -- 50 Rupees - 3 Tumbleweeds, 3 Monster Claws, 2 Eldin Ores, 1 Evil Crystal
Large Bomb Bag (Upgraded from Medium Bomb Bag) -- 100 Rupees - 3 Lizard Tails, 4 Jelly Blobs, 2 Hornet Larvae, 1 Golden Skull
Large Quiver (Upgraded from Medium Quiver) -- 100 Rupees - 2 Monster Horns, 3 Dusk Relics, 1 Golden Skull, 1 Goddess Plume
Large Seed Satchel (Upgraded from Medium Seed Satchel) -- 100 Rupees - 5 Amber Relics, 3 Monster Claws, 1 Golden Skull, 1 Blue Bird Feather
Medium Bomb Bag (Upgraded from Small Bomb Bag) -- 50 Rupees - 1 Lizard Tail, 3 Ornament Skulls, 1 Blue Bird Feather
Medium Quiver (Upgraded from Small Quiver) -- 50 Rupees - 3 Monster Horns, 3 Dusk Relics, 5 Amber Relics
Medium Seed Satchel (Upgraded from Small Seed Satchel) -- 50 Rupees - 4 Amber Relics, 3 Monster Claws, 3 Ornament Skulls
Quick Beetle (Upgraded from Hook Beetle) -- 50 Rupees - 2 Ancient Flowers, 2 Hornet Larvae, 1 Golden Skull
Reinforced Shield (Upgraded from Iron Shield) -- 50 Rupees - 2 Eldin Ores, 2 Ornament Skulls, 2 Monster Claws
Sacred Bow (Upgraded from Iron Bow) -- 100 Rupees - 5 Tumbleweeds, 3 Lizard Tails, 2 Evil Crystals, 1 Goddess Plume
Scattershot (Upgraded from Slingshot) -- 50 Rupees - 2 Dusk Relics, 2 Amber Relics, 3 Jelly Blobs
Tough Beetle (Upgraded from Quick Beetle) -- 50 Rupees - 3 Ancient Flowers, 4 Amber Relics, 1 Blue Bird Feather, 1 Goddess Plume

Complete the game and defeat the lastboss on Hero Mode, then save the game after the credits to unlock the Triforce Emblem on your gamesave.

Don't purchase anything from Beedle's Shop and try to leave. Beedle will open a trap door and you will fall to the ground below.

The theme song of the game is actually "Zelda's Lullaby" from The Legend Of Zelda: The Ocarina Of Time played backwards.

Climb around to the roof over Zelda's room using the ledge by the upper entrance to the Knight Academy. Use the Clawshots on the target on the top of the chimney's reverse side to go insie the academy. Note: If done at night, Gaepora will be taking a bath below where you land. Crawl through the passage to enter Zelda's room. Once there, look at Zelda's Diary by sitting in her chair; get a Gratitude Crystal (at night); get a Heart Piece from the cabinet; and look at the Tingle doll.

Find the following Heart Piece by searching the corresponding locations:

Goddess Cube, Deep Woods
Activate the Goddess Cube outside the Skyview Temple entrance. The chest can be found on a small island south of Skyloft.

Goddess Cube, Temple of Time
There is a mine cart and a robot blocking the path that upgrades your map to have several waypoints in the area outside the Temple of Time . The Goddess Cube is east from here, along the mine cart track. Use the Timeshift Stone above the area to push or ride the mine cart to the edge of the Timeshift Stone's effect. There is another stone across the gorge. Activate it with the Hook Beetle and get in the mine cart. Charge a Skyward Strike and hit the Goddess Cube as the mine cart passes it. The chest can be found on Beedle's Island in the northeast of the sky.

Goddess Cube, Faron Woods
Note: This requires the Water Dragon's Scale. Get access to the top of the Great Tree in Faron Woods. Drop off the ledge on the northeast side of the tree. Fall to the platform with the Goddess Cube. Note: This cube can be seen from the viewing platform with the Bird Statue in the north.

Goddess Cube, Pirate Stronghold
Note: This requires the Clawshots. Open the jaws in the Pirate Stronghold and get outside. Turn around and look for a high Clawshots target. This will lead to the Goddess Cube.

Goddess Cube, Volcano Summit
The cave leading to the Fire Sanctuary entrance has an exit that leads to a waterfall. Use the water to put out the frog statue flames. Run off the cliff by this waterfall and fall down. Maneuver around a pillar to land on the platform with the Cube.

Goddess Cube, Eldin Volcano
Note: This requires the Water Dragon's Scale. There is a long sand slide on the eastern side of Eldin Volcano, in the far north. Take the left side and aim for the left platform that has a Dig Spot. Below this is another platform with a Goddess Cube. The chest is in the center of the town of Skyloft. Note
You must swim underwater to reach the area it is in.

Between Sealed Grounds and Faron Woods
Gorko will give you a Heart Piece after you showing him how to draw a heart symbol on the Goddess Wall by the shrine entrance.

Eldin Volcano
The Heart Piece is above the area in the southwest of Eldin Volcano. Send the Beetle past it then run it into a bomb by the shelled Pyrup to take it out. Set a waypoint marker on your map to it, then run all the way around and collect the Heart Piece.

Faron Woods
Note: The Bomb Bag is required. Destroy the bomb-able wall near the entrance to the path to the Sealed Grounds on the west side of Faron Woods proper.

Faron Woods
The central tree in the northern portion of Faron Woods has a root that in the south that leads to a rope. Use it to cross to the Heart Piece.

Fire Sanctuary
Note: The Mogma Mitts is required. Find the dig spot in the northwest corner of the Fire Sanctuary, just before the river of lava. Catch a Mogma in the tunnel to get the Heart Piece.

Fun Fun Island
Repair Fun Fun Island and get a perfect score in the Dodoh's Drop game. To do this, drop through all five rings to get a x10 score multiplier and land on the 50 Rupee multicolored space.

Lanayru Desert
Note: The Clawshots is required. Open the bombable wall found in the northeast of Lanayru Desert proper. Proceed ahead to a long path of Clawshots targets and Chuchus. The Heart Piece is in a chest at the end.

Lanayru Gorge
Revive the Thunder Dragon then play Lightning Round/Boss Rush mode. Defeat four consecutive bosses and quit to collect the Heart Piece.

Pumpkin Landing
Complete all of the tasks for the owner of the Lumpy Pumpkin (Pumpkin Soup delivery, Pumpkin Harvest, and Kina's song).

Pumpkin Landing
Go inside the Pumpkin landing pub and run upstairs. Roll into a rafter to bring down the Heart Piece.

Sandship
Note: The Clawshots is required. Make your way through the crow's nests of the Sandship to get access to the rear of the ship. Use the Clawshots to reach a Clawshot Target that lets you drop down the back side of the ship. A chest there has the Heart Piece.

Shipyard
Complete the Sandship and return to the Shipyard. Play the Rickety Coaster game and complete the Expert course in 65 seconds.

Skyloft
Take ten Gratitude Crystals to Batreaux.

Skyloft
Complete the Fledge's Workout side quest. Find Fledge in the pumpkin patch on Skyloft, then score 600 points in the Pumpkin Pull game.

Skyloft
Note: The Clawshots is required. Enter Zelda's room. You can see the Heart Piece through a crack in Karane's wall. Climb to the roof of the Knight Academy and aim the Clawshot under the roof of the chimney. Release and fall into a room above the bath. Climb through the small hole and drop into Zelda's room. Open her cupboard to find the Heart Piece.

Skyloft
Buy the Heart Piece in Beedle's Shop for 1,600 rupees after getting a wallet large enough to hold the funds.

Skyview Temple
Get the Beetle and use it to hit a switch above the bottle-like structure to open a gate to the Heart Piece.

Volcano Summit
Note: The Mogma Mitts are required. Find the Gossip Stone with a dig spot in front of it at the entrance to the Fire Sanctuary. A Heart Piece can be found there.

In Hero mode, consecutively defeat eight Bosses in the Boss Challenge at Lanayru Gorge.

There are three attacks you can do after charging the Skyward Strike:

Horizontal Slash / Vertical Slash - A circle of energy cuts through enemies
Thrust - A "beam" of energy is released that travels a bit further than a slash
Spin Attack - Your Spin Attack will have a larger radius

Use the hookshot on the chimney on the roof of the academy in Skyloft to find a hidden passage into Zelda's bedroom. On her desk is a small Tingle plush toy.

If you take out either your bug net and wave it around, Demise will follow it around just like with Ganondorf in Twilight Princess.