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