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