Here is the full list of all 60 Littlewood achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Catch 500 bugs.
Upgrade all structures and areas to 10 stars.
Complete 50 quests.
Mine 1500 ores.
Catch 250 fish.
Meet 15 Townsfolk.
Catch 250 bugs.
Harvest 500 crops.
Gather 500 items.
Craft 1000 items.
Sell 700 items.
Complete 25 quests.
Catch 100 fish.
Mine 750 ores.
Catch 100 bugs.
Chop 750 trees.
Complete 10 quests.
Craft 500 items.
Sell 300 items.
Meet 12 Townsfolk.
Harvest 100 crops.
Meet 10 Townsfolk.
Craft 250 items.
Mine 150 ores.
Gather 100 items.
Chop 150 trees.
Craft 100 items.
Sell 50 items.
Sell 100 items.
Meet 3 Townsfolk.
Meet 5 Townsfolk.
Gather 1000 items.
Gather 2500 items.
Gather 4000 items.
Mine 3500 ores.
Mine 6000 ores.
Chop 1500 trees.
Chop 3500 trees.
Chop 6000 trees.
Catch 1000 bugs.
Catch 2500 bugs.
Catch 500 fish.
Catch 1000 fish.
Catch 2500 fish.
Harvest 1000 crops.
Harvest 2500 crops.
Harvest 4000 crops.
Craft 2500 items.
Sell 1500 items.
Complete 100 quests.
Complete 150 quests.
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.
Unlock all ultimate upgrades at the Crafting Workshop.
Donate all items to Museum.