I must say I am a little disappointed with Book 3. Let me explain why, and I will avoid spoilers - just to mention at the beginning of the post
Firstly, from the aspect of storytelling - I think a great job has been done. They have proven that they can make a culmination, and in my opinion, lived up their reputation from TLJ and DF. This goes especially for the very beginning of Book 3, which was ABSOLUTELY MINDBLOWING! Goosebumps all over the place, and no one got burned, indeed
Secondly, I think it was a little too short... Way too short. I think this is a consequence of two-three things:
1.) It was indeed not that much happening, especially compared to Book 1, and 2
2.) I felt as a passive "player", more of an observer than a player of game. I felt as if I am kinda watching a movie (I think there were thoughts like this elsewhere in the forum already). I think that some dialogues were a little too rushed through - and I can barely remember more than 3-4 places where there player could contol the conversation. And there were PLENTY of places in the game where this could have been done very well, as in the previous books and in TLJ. I simply felt left out, except when it came to those important choices, which were like, a sudden shake while I already got used to sitting back and simply whatching the story unveils.
3.) I think there could have been more things to say about both Propast and Marcuria, through player-controlled dialogues. I kinda miss that soul-filling information about the worlds when you talk to someone - and when someone is away for two months, then she really has to wonder about what and how - and all that could have been done through dialogues.
However, one must not forget that Book 3 is a part of the FULL game, which is going to turn out to be pretty long, in the style of the previous games, which I salute with gratitude Book 3 featured short chapters, something similar to having Chapter 6 from TLJ (on the ship to Alias) and a little bit more. So Imagine dividing TLJ into 5 parts - and some part would indeed be shorter, compared than others. So I think that the feeling of having each Book as a separate game is a little to hasty to have, when you look at it from this perspective, and therefore statements like "it was too short" or "too long" should be taken with care. The big picture matters. This being said, the long cutscenes might be compared to the scene of Flipper and April from TLJ, for example, when he was telling her about what is going on with Vanguard and all that. However, even this taken as such, it is still not a good comparison, because April didn't really talk much during that scene (and the scenes alike), unlike Kian and Zoe in Book 3. There where really quite a few places in the game where I was like "wait, why don't you let me pick what to say and in which order?!" But back to the point - if one takes all three books up to now as a full game (or will-be full game in several months), then I might swallow this not-so-tasty bite of disappointment.
Oh, regarding puzzles - I have a general disliking opinion regarding the puzzles in DF and DFC, compared to TLJ, but if I try to leave that biased opinion, then puzzles so far were very creative (apart from the animal abusing one) and I like that fact that there were several ways of solving a problem - so we had a choice even in solving puzzles, which is something new (although that doesn't compensate the lack of choices in dialogues).
It also feels somehow as if RTG was on a time pressure... Some things I felt were done a little too hasty - no animations for taking/leaving an object to the interactable spot (it just appears mysteriously and that kinda spoils the feeling :/ ), objects that are missing from the time befire the cutsceene in the same location... I guess one has to take into account that they are only, what, 8 people???? woriking on this amazing game, and that IS something.
All in all, if I take Book 3 as a part of the whole game, then I can make myself be happy about it. But compared to Book 1 and 2, Book 3 feels like a step backwards, from the aspect of gameplay. From the aspect of storytelling - A+, no arguing with that. But a good storytelling in a game is always better to involve the player. They indeed set the standards and expectations with Books 1 and 2.