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