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