As others have already stated, the latest - and last - game in the Professor Layton series is just as good, if not better than the games that came before it. I have played all the Layton games since the first one was released in the UK years ago, and I can honestly say that if you enjoy puzzle games in general, you'll enjoy this game. If you like a good storyline to go with your puzzles, then you definitely need to pick up this game.
The graphics are sharp and clean, the music charming as always (like the other Layton games), the puzzles are sufficiently tough enough that even when you come across another puzzle similar to one you've solved before, it'll still tease the little grey cells the second (or third!) time around.
I can't recommend this game enough; however, like others have said as well, if you've never played a single Layton game before, it's probably not a good idea to start with this one. Play them in chronological order of when they were released to get the most out of the main plot of this series.