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