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