Great point a click game and definitely the best one in the series.
The story is impressing and I would recommend translating it to a movie. The graphics are great and the voice acting is awesome, probably done by the same actors who worked on the previous projects not really sure about that. Also the graphics are colorful and intense taking point and click adventure games into the next generation with a triumph.
The game is somewhat long and requires many hours of game play for solving the puzzles which as I said earlier are quite hard with the use of the word input system that somewhat need to be refined for other versions to come, not that its no good, its just that it might need refining a little bit to cover all bases since sometimes alternative words can be used but sadly it doesn't work so you'll have to take a short cut and read a walk-through to pass them.
All in all its a great game, great puzzles, great story and the best in the series so far. The only downside of it is that it requires a lot of back and forth moving which almost takes most of the playing time. Of course the map hot spots that are updated as you play are quite useful but sometimes you just have to do things the hard way especially when you're missing something.
Now I'm waiting for the fifth installment of the series, Jack the Ripper I'm lusting for you.