Here is the full list of all 28 Staxel achievements.
The base game contains 23 achievements, and there is 1 DLC pack containing 5 achievements.
Shear a Sheep 100 times
Milk a Cow 100 times
Catch one of every fish
Catch one of every bug
Catch 100 Fish
Bake one of each Pie
Cook one of each Preserve
Bake one of each Cake
Plant 1000 Seeds
Cook one of each Soup
Gather 100 Mushrooms
Deliver your farm registration letter to the mayor
Gather 100 Shells
Sweep a ball
Mine 1000 Raw Stone
Use a wardrobe to change your outfit!
Loot a forest treasure chest
Find 100 Mixed Seeds
Reap a Gold Seed
Throw a ball
Catch 100 Bugs
Chop 1000 Raw Wood
Harvest Star Jelly
Harvest Grapes, Artichokes, Purple Nettle and Rhubarb
Cook Couscous and Baked Artichoke with Goats Cheese
Collect Goats Milk and Brown Pheasant Feathers
Catch one of each bug found on the Galaxy Island.
Catch one of each fish found on the Galaxy Island