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