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