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