Scattered throughout the island are 26 Secret Seashells. If you collect 20 seashells, you can get a more powerful sword, capable of ranged attacks.
- Item needed: Sword
Slash the bushes out of the way to find your first Secret Seashell.
- Item needed: Shovel
Dig in Bow-Wow's kennel for a second Secret Seashell. It is found in the bottom-right corner.
- Item needed: Bombs
From the entrance of tail case, head north, west, and north. You should see a cracked wall on the left. Use a bomb, and collect the chest.
- Item needed: Power Bracelet
In the mysterious forest, one of the southern parts of the forest has a chest behind a rock. Lift the rock, then open the chest.
- Item needed: Power Bracelet, shovel
Take the east exit of the mysterious forest, and head south. Lift the rock. You should see a lone bush, which may be removed, and dug.
Enter Seashell Mansion with exactly 5 seashells.
East of the seashell mansion, slash the upper two bushes to reveal the shell.
North of the mermaid lake, you should see a stone. Lift it.
North-west of Martha's bay is a cave. Enter it, and head to the left wall with a different floor tile; tap it with your sword to confirm if it can be bombed, and go through. At the end of that tunnel and cave, you should eventually reach an owl statue, which you can dig around.
After completing Bottle Grotto, look for mermaid lake. It is located in the same area as the mermaid statue. Chop the bush to get it.
Enter the seashell mansion with exactly 10 seashells.
When you collected five gold leaves, you can enter the tunnel below Richard's Villa. Take the left path, push the block forward, and open the chest.
To the right of the Key cavern, there is a stairway leading up. Head left one screen, and you should see a clear patch between four grass patches. Dig here.