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