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