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