Here is the full list of all 18 Queen's Quest 3: The End of Dawn achievements. It takes around 4-5 hours to unlock all of the achievements on Windows.
Finish every the Mini-games without skipping any of them.
Defeat the Dragon Lord.
Destroy the machine powering the crystal.
Finish every Hidden Object Scenes without using a hint.
Find every Collectable.
Complete the ritual.
Complete a Hidden Object Scene in less than one minute.
Return the crystals to the witch.
Find 30 Collectables.
Complete three Hidden Object Scenes in less than 10 minutes.
Find the Dragon Crystals.
Open the library.
Complete five Mini-games without skipping them.
Complete a Mini-game in less than one minute.
Complete a Hidden Object Scene without using a hint.
Complete a Hidden Object Scenes without mistake.
Find 3 hidden objects in three seconds.
Find one Collectable.