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