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