That's perfect because there are a few puzzles not up to the same standards as the really great ones, and for the record, the majority of the puzzles are great. Take out some of the poorly translated dialogue, which will likely mean some characters and puzzles will have to be eliminated altogether. Let me just jump right in and tell you what I'd slash.
It's not important to have 15 hours of gameplay when you could have 10 hours or less of quality gameplay time. It's amazing how some filler can contaminate an otherwise pristine presentation. Cut out the crap, tighten it up, lose a few hours, and you'll have something astounding at your fingertips. Everything that conspires to make The Whispered World a mediocre, point-and-click adventure game is also contained within. Everything needed to make The Whispered World a truly great video game is all contained within the game.