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