Here is the full list of all 38 Castaway Paradise Complete Edition achievements.
Grow every type of flower
Donate all shells
Donated every collectable
Remove 25 cobwebs
Donate all fish
Rebuild the Lighthouse
Grow every type of crop
Grow every type of fruit
Completed 100 quests
Rebuild Angus' Trailer
Rebuild Francis' Pirateshack
Changed every piece of outfit
Wore an outfit of the opposite gender
Donate 15 shells
Rebuild Amelia's Planehouse
Make a profit of 2000 gems at the Bank
Make a profit of 5000 gems on the Stock Market
Rebuild Victoria's Mansion
Donate 15 fish
Live the luxury life of a VIP
Donate all bugs
Used every piece of equipment
Read 50 chit chats
Unlocked a gate
Donate 15 bugs
Remove 50 weeds
Donate a collectable
Rebuild Harold's Museum
Collect 25 pieces of garbage
Unlock the second room in your house
Completed 25 quests
Harvest 50 crops
Rebuild a bridge
Rebuild Gustave's Bakery
Make a profit of 500 gems on the Stock Market
Remove 25 stones
Get your first collectable
Completed the tutorial