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.
Find everything in the game
Solve all ancient temple puzzles
Dig up a talisman of the gods
Craft every item you can
Buy all the multivitamins
Find every Kamasutra page
Light all torches
Fully impress Jim
Complete the main story
Dig up a royal talisman
Dig up a grand talisman
Catch a great white shark
Buy everything from the bait shop
Dig up a gold talisman
Catch a hammerhead
Catch a tuna
Catch a rockfish
Dig up a silver talisman
Catch a seaperch
Dig up a jade talisman
Dig up a stone talisman