Here is the full list of all 31 Yoku's Island Express achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Complete Thorn quest
Collect every ability upgrade
Complete Rinri's quest
Get the biggest wallet
Unlock all treasure chests
Complete Willo's quest
Activate all Scarabs
Hatch the God Egg
Collect all Wickerlings
Try every ball style
Become the Postmaster
Discover the heart cluster at the bottom of the sea
Take the surviving egg to Dipperloaf
Customise Yoku’s ball
Complete the story
Deliver the cake to the inventors house
Discover Fosfor’s Lair
Toot the noisemaker 1000 times
Unlock all the Beelines
Defeat Screetch
Complete the temple trials
Collect the Divefish
Defeat the Spider
Befriend a Sootling
Find the Post-office
Ride the Beeline
Save Spina
Suck up a slug with the Slug Vacuum
Toot the noisemaker 100 times
Free Kickback
Blow the noisemaker