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