Here is the full list of all 21 Treasure of Nadia achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Buy all the multivitamins
Dig up a royal talisman
Dig up a talisman of the gods
Dig up a grand talisman
Solve all ancient temple puzzles
Buy everything from the bait shop
Fully impress Jim
Dig up a gold talisman
Catch a seaperch
Catch a rockfish
Catch a tuna
Catch a hammerhead
Catch a great white shark
Dig up a silver talisman
Dig up a jade talisman
Dig up a stone talisman
Find every Kamasutra page
Find everything in the game
Craft every item you can
Complete the main story
Light all torches