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