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