Here is the full list of all 12 Merchant of the Skies achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Restored botanical garden
Fed the Fish God
Built a lighthouse
Supplied inns with bread and apple juice
Put money into bank
Completed the Money Accumulation goal
Bought an island
Bought a new ship
Found the Giant Island
Completed first quest
Fueled a ship