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