Here is the full list of all 60 Littlewood achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Complete all Personal Goals.
Harvest 4000 crops.
Catch 2500 fish.
Donate all items to Museum.
Find all Tarott Monster cards.
Gather 4000 items.
Complete 150 quests.
Catch 2500 bugs.
Visit the Edge of Solemn.
Unlock all town wishes.
Unlock all ultimate upgrades at the Crafting Workshop.
Harvest 2500 crops.
Chop 6000 trees.
Mine 6000 ores.
Chop 3500 trees.
Discover All Tavern Recipes.
Gather 2500 items.
Mine 3500 ores.
Craft 2500 items.
Get Married.
Catch 1000 fish.
Upgrade all structures and areas to 10 stars.
Complete 100 quests.
Catch 1000 bugs.
Sell 1500 items.
Harvest 1000 crops.
Adopt a pet.
Chop 1500 trees.
Mine 1500 ores.
Catch 500 fish.
Complete 50 quests.
Harvest 500 crops.
Gather 1000 items.
Catch 500 bugs.
Meet 15 Townsfolk.
Craft 1000 items.
Complete 25 quests.
Sell 700 items.
Mine 750 ores.
Catch 250 fish.
Chop 750 trees.
Gather 500 items.
Meet 12 Townsfolk.
Craft 500 items.
Harvest 100 crops.
Catch 250 bugs.
Complete 10 quests.
Sell 300 items.
Catch 100 fish.
Meet 10 Townsfolk.
Catch 100 bugs.
Craft 250 items.
Mine 150 ores.
Sell 50 items.
Sell 100 items.
Gather 100 items.
Craft 100 items.
Chop 150 trees.
Meet 5 Townsfolk.
Meet 3 Townsfolk.