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