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