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