Island Challenges:
Bouncer: Bounce an enemy with a shield 10 times.
25 Diamond
Ceramic Killer: Kill an enemy with a jar.
50 Diamond
Making Friends:Release the Direfolk’s prisoner.
100 Diamond.

Heart Piece:
1. After you meet up with Rigger and obtain the object creation spell, you will find the heart piece in the cave after.

Bloodstones:

First Visit:
Your first visit to the Island is pretty unfruitful. You will move about on the island until you see a man who mentions that he cannot pass. He should have gotten some bombs from Bomb Island. So now head to the Bomb Island and get some bombs.

Second Visit:
After unlocking the use of bombs on Bomb Island, you have received a note to save a prisoner from the island. Progress through the island to save Rigger.

After saving Rigger you will be given a clue to go to the Great Forest. He will also reward you with a Force Spell to create objects out of thin air. Remember to pick up the Heart Piece inside the cave after saving Rigger before you leave the island.