Good story, great gameplay, great riddles, much better than AoM: FBI Confidential and Chronicles of Mystery.
+ First of all it has an interesting plot. Personally I'm quite into the marionette topic recently because of two great Hamasaki Ayumi videoclips and one concert performance so I was anticipating this game a lot. The story is building up suspense, it makes you want to see what will come next, I finished it in two days not because it was short but because it sunk me in for many hours till late at night.
+ I saw people praising the riddles but complaining about the one that opens hidden passage in Louis' manor, I do agree it's a bit illogical to have a fifteen puzzle as a door lock but it wasn't the unsolvable one, with tiles 14 and 15 exchanged, so it wasn't difficult at all. I must say the riddles were well-thought, e.g. close the window and the shadow of a stain on it will reveal the hiding place, repair the bucket and fill with water to use it as a lever and open a trap door, lots of logical thinking needed, I didn't have to use a walkthrough not even once. There are also some time trials but they were relatively easy, you will complete most of them in one go, although there were some confusing and funny ones, e.g. I was pretty sure I must carry water in broken carrier bag to one car but I couldn't fill the radiator with it, I didn't know if I I have lost too much water or maybe I need some kind of funnel, it occurred that this wasn't a time trial at all I had to repair the bag and pour the water to completely another car radiator, lol.
+ Nowadays people seem to prefer games that take place in real time only, that cut scenes only mess up and are out of date, well, if you also think so then take this point as a disadvantage because this game has lots of fantastic, dynamic movies which add variety to the gameplay.
+ Graphics and music. It's a traditional third person perspective point and click game, I'm happy there are still games like that, I'm scared that any moment all adventure games will become full 3D like Dreamfall. Locations are vivid and lively even if dark and gloomy whenever the plot requires it. I really liked the environment, especially the ballet room, Jack's apartment, hotel and the second-hand bookstore. Although I'm a Tomb Raider fan, I'm not fond of wild grounds that much, but even though I didn't enjoy the Havana that much I can still appreciate the effort authors put in those locations. As it goes for music, I don't remember it (again!, same goes for CoM), but I remember how I loved the sounds in cutscene videos and they were very good.
+ It's the first time I remember ALL characters from a game, it's also the first (maybe second) time I find the main protagonist being not as good and well thought out as the background characters. I especially liked the owner of the hotel, it's funny how such inconspicuous person can cheer up the atmosphere.
I don't know if the game has any disadvantages. I didn't encounter any bugs, I didn't stuck, it didn't crush. I guess the only flaw it has is that the game is 'only' very good / solid one, instead of being an extraordinary game. Unfortunately it's still behind games like, again, Still Life or Syberia but luckily it's better that other games from the same studio so we can see the creators are learning and make their products better each time. I really hope I'll be able to give at least 9.0 to their next game!