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