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