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