Here is the full list of all 39 Spiritfarer achievements. It takes around 35-40 hours to unlock all of the achievements on Windows.
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Complete all collections
Discover all recipes
Use Alex's bus stops 50 times
Fully improve Buck's Lair of Wonders
Fully improve Elena's Cubicle
Activate all the shrines
Collect all figureheads
Light up all Lighthouses
Make all spirits reach the ecstatic mood at least once
Shear sheeps at least 50 times
Endure 10 of Albert's jokes
Tell Astrid about Giovanni's night excursions
Give a dating advice
Accomplish your very last objective
Bring all releasable spirits to the Everdoor
Complete thirty errands for Francis
Build all houses and stations at least once on the boat
Have your final conversation with Hades
Fully improve Gustav's Gallery
Fully improve Bruce and Mickey's Crib
Sell at least 200 items
Find and shelter all sheeps
Fully improve Astrid's Bungalow
Have your second conversation with Hades
Do not tell Astrid about Giovanni's night excursions
Fully improve Atul's Workshop
Complete twelve errands for Francis
Fully improve Stanley's Playroom
Fully improve Alice's Cottage
Buy at least 100 items from Raccoon Inc
Make 5 spirits reach the ecstatic mood at least once
Sign up to Feedorama
Have your first conversation with Hades
Fully improve Summer's Sanctuary
Fully improve Gwen's Lodge
Give Furogawa Tour's guide a tip
Complete one errand for Francis
Make one spirit reach the ecstatic mood at least once