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
Supplied inns with bread and apple juice
Fed the Fish God
Built a lighthouse
Completed the Money Accumulation goal
Put money into bank
Bought an island
Found the Giant Island
Bought a new ship
Completed first quest
Fueled a ship