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