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