Read all letters.
Complete a cairn.
Activate a fresco.
Complete the game.
Scare more than 10 chocos back to their burrow.
Hug the ballast.
Hug the ballast 20 times.
Stop 25 pebbles with a single echo from the ballast.
Read all of Bianca's journal entries.
Use the echo on a frozen ballast in the crater.
Listen to all shells.
Turn all altars.
Activate all frescos.
Complete all cairns.
Read a letter.
Turn an altar.
Listen to a shell.
Use the echo on a frozen ballast in Chapter 6.
Obtain all trophies in the game.