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