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