Full list of all 33 Island Saver achievements worth 2,000 gamerscore. It takes around 6-8 hours to unlock all of the achievements in the base game on Xbox One.
The base game contains 13 achievements worth 1,000 Gamerscore, and there are 2 DLC packs containing 20 achievements worth 1,000 Gamerscore.
Complete charity mission and send Litterbugs home
Exchange all 5 currencies into doubloons at least once
Exchange any currency at its best price
Repay a bank loan
Deposit 1000 gold doubloons
Take out a bank loan
Barter with Kiwi
Use tax to build a bridge
Earn 50 Tax Tokens
Spend 100 in Pigby's Store
Earn first interest on your savings
Deposit 100 gold doubloons
Use tax to empty recycler
Open the Electric Gate
Use T-Rex to smash amber
Ride on an Ankylosaurus
Ride on a Velociraptor
Insert battery into Giant Tax Bot
Feed a flying Pteranodon
Help Newton repay all his debts
Build tax bridge
Collect a piece of broken Exit Bot
Find all Newton's lost fossils
Help smoothie stall re-open for business
Use a magic portal
Smash a wooden crate
Glide on a dragon
Build portal pipe on Hub Island
Paint both billboards on Oasis Island
Plant a giant beanstalk
Find Truffles's lost dog
Awards all fruit supply contracts
Find all the Golden Goose eggs