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