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
Complete all collections
Discover all recipes
Sell at least 200 items
Unsubscribe from Feedorama
Buy at least 100 items from Raccoon Inc
Activate all the shrines
Shear sheeps at least 50 times
Collect all figureheads
Light up all Lighthouses
Bring all releasable spirits to the Everdoor
Fully improve Elena's Cubicle
Find and shelter all sheeps
Build all houses and stations at least once on the boat
Have your final conversation with Hades
Make all spirits reach the ecstatic mood at least once
Fully improve Buck's Lair of Wonders
Fully improve Gustav's Gallery
Use Alex's bus stops 50 times
Have your second conversation with Hades
Fully improve Alice's Cottage
Fully improve Astrid's Bungalow
Fully improve Bruce and Mickey's Crib
Complete thirty errands for Francis
Sign up to Feedorama
Tell Astrid about Giovanni's night excursions
Fully improve Atul's Workshop
Fully improve Stanley's Playroom
Endure 10 of Albert's jokes
Give a dating advice
Complete twelve errands for Francis
Make 5 spirits reach the ecstatic mood at least once
Fully improve Summer's Sanctuary
Have your first conversation with Hades
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