Here is the full list of all 12 Chessformer achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Complete 4 levels.
Complete 8 levels.
Complete 12 levels.
Complete 16 levels.
Complete 20 levels.
Complete 24 levels.
Complete 28 levels.
Complete 32 levels.
Complete 36 levels.
Complete 40 levels.
Complete 44 levels.
Complete 48 levels.