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