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