Oracle of Seasons Heart Pieces
Link begins the adventure through Labrynna with three full Heart Containers. There are twelve quarter Heart Pieces scattered throughout the game. There is also full Heart Container to snag after each boss, bringing Link's total life to fourteen hearts after obtaining each Heart Piece and Heart Container.
Heart Piece #01
Location: Horon Village
Heart Piece #02
Location: Woods of Winter
In the Woods of Winter, go to the stump in the southeastern corner (two screens right from Horon Village). Change the season to winter and go up one screen, and then go left after you go up the snow. Go into the cave and collect the Piece of Heart.
Heart Piece #03
Location: Woods of Winter
Start from Horon Village and go east into the Woods of Winter. Go to the stump right a screen and change the season to winter. Go back left one screen, up once, right once, and up three times. Now head right twice, down once, and right two more times. Use your Power Bracelet to lift the rock blocking the way, or just swim to it.
Heart Piece #04
Heart Piece #05
Location: Eyeglass Lake
Head to the stump near Unicorn's Cave and change the season to summer. Head down twice, go down the stairs and head one more screen up. Pick up the rock and go downstairs. Now just follow the path, while fighting off the monsters, and collect your Piece of Heart from the chest.
Heart Piece #06
Location: Moblin's Keep
From the entrance to Sunken City, head up one and left two screens along the path, then head down three screens and right one. Cross the bridge and swim across to the steps. Walk up them and continue up two screens and enter the Moblin’s Keep. Head up the staircase here to face off against the Moblin King. Throw the bombs back at the king to defeat him, bringing the tower down. A chest containing a Piece of Heart can be found in the rubble.
Heart Piece #07
Location: Spool Swamp
Go to Spool Swamp and go one screen south from the Poison Moth's Lair. Use the stump to change the season to spring and go right. Go down three and right two screens. Head down a screen here and use the current to go left. Pick up the Piece of Heart lying here.
Heart Piece #08
Location: Mt. Cucco
From the Dancing Dragon Dungeon, simply jump down the gap in the southern wall and collect the Piece of Heart.
Heart Piece #09
After the Piratians dock up near the Graveyard, head to the stump in this area to change the season to autumn. Now return through the house and follow the path to the Graveyard. Enter the cave along the way. Go in and use Roc's Cape to jump across the gap. Exit the cave to arrive in the Graveyard. Head to the entrance of the Explorer's Crypt where you see mushrooms. Pick them up, head right a screen, and snag the Heart Piece.
Heart Piece #10
Location: Temple Remains
After the volcanoes erupt in Subrosia, you will find a cracked wall in the northern section of the Temple. Use a Bomb to reveal the entrance to the cave. Inside, make your way to the Heart Piece at the back of the room, with the help of Roc's Cape.
Heart Piece #11
When meeting with Maple, she may drop a Piece of Heart as she rides around. This is completely random, and will take a few tries to obtain. If you have Maple's Ring, equip it, as this will halve the amount of enemies you need to defeat to force Maple to appear, from 30 down to 15. A good place to farm encounters is in the past. Head to the Black Tower and defeat either 15 or 30 enemies, depending on if you have the ring. Once you have done this, leave the tower, head back to Lynna Village and out to the east, where Maple will appear. If she drops the Heart Piece, she will immediately head towards it, so it can be difficult to snag.
Heart Piece #12
This Heart Piece requires opening a Gasha Nut, produced after a Gasha Seed is planted. Seeds planted in more difficult-to-reach locations have a higher chance of producing a Nut which contains rare items, which includes the Piece of Heart. Keep planting until you obtain this Heart Piece.