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