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