My (now 8-year-old) daughter and I read The Golden Compass and finished it the same night we watched this on Amazon. We were both disappointed, her especially.
For those who've read the book, as to be expected there were many shortcuts, twists of the story to suit something faster-paced and characters conflated or just not given adequate attention to feel like you knew what their personality or motives were.
But beyond this, the movie just seemed like a rush to get through as many scenes from the book that they could manage, without really much of any character development. IE, all plot and little character. I feel like I have to go back and re-watch it because I'm sure I missed a lot because it was so rushed.
The movie did do a great job visualizing everything in the book. For the most part, everything was more or less how I had imagined this world to be. Unfortunately, because of the pacing, one didn't get a great chance to really admire all that scenery, because it just went by too quickly.
Due to that speed, I would guess that those who hadn't read the book would by and large be somewhat confused about the point of all this. To them it probably seems like just a crazy fantasy adventure with animal spirits and odd steampunkish devices and vehicles.
**Spoiler alert: I'll try to details some of the things I missed from the book that would have made a difference, so if you don't want to know about some of the details of the movie/book, you might want to stop reading.**
There was almost no talk of the aurora or the city in the sky, something central to the book. They do mention mention dust once or twice, but it's mostly Lyra suddenly figuring out what dust is on her own. The only time there's discussion of it by an adult I think is in the initial scene with Lord Asriel at Jordan.
Lyra's character was plucky but had very little range. There are numerous times in the book where she cried quite a bit. I guess crying in the movie would have meant either too much time, or somehow would have shown her not to be "strong." You got a tiny glimpse of how Lyra could lie/spin a yarn, but just barely.
Lord Asriel was in the movie for all of two minutes probably.
There was a scene in the movie that was not in the book that made zero sense - Mrs. Coulter slapping her daemon, then comforting it. We haven't read the other two books in Pullman's series, so maybe this presages something in one of those? But I kind of doubt it. The only thing I can think is that either Mrs. Coulter has been separated from her daemon or she is a masochist, because you are supposed to feel everything your daemon feels - something the movie actually shows well for other characters.
In general, the movie leaves out the more disturbing scenes, possibly because they thought they were too dark for a younger audience? For example, while they do show the scene where Lyra discovers the child who's daemon has been separated from him (albeit it's a different character from the one in the book), at the end the import of this is spoiled because a) the child does not die, and b) his mother, comforting him, acts as if it's like he's lost a pet which she promises to find for him. There is none of the shock of this, only a few signs that this might be more serious than losing a pet. That's another omission here, although they mention at the very beginning that the animal daemon is part of the person's soul, they don't reinforce this with any other statement throughout the book. About the only other indication is when a daemon (I think it's mainly just Pantalaiman) is attacked once or twice and it's human seems to feel it's pain. So the whole idea of "severing" doesn't have nearly the import it does in the book. I can imagine those who haven't read the book scratching their heads as to that whole idea, and just not getting that it was about the worst thing imaginable - even worse than death - for most people of this world.
The movie didn't even include the final scene of the book - the opening of the bridge to the other world.
Again, it was really disappointing from an adaptation point of view. It was interesting to see the visualizations, but ultimately frustrating due to the limitations of film. Peter Jackson made The Hobbit, a book much shorter than The Golden Compass, into a three-part movie. If this movie had been given that degree of attention and breathing room, it could have really been much better, even great.
It all comes down to money I guess. Authors and publishers want to make money selling the film rights, and movie studios want to translate that investment into ticket sales and DVD rentals (or whatever the equivalent is for streaming) as quickly as possible. It does take someone with deep pockets, vision, stubbornness and perhaps just their own movie studio, to pay adequate homage to a longer book that is relatively complex. It's seldom done, and so we end up with very mediocre stuff like this film, which is ok for a family movie night, but probably never watched afterwards. It pales so much in comparison to the book. If you are watching this with your kids, I would highly recommend reading the book to them or have them read it, because it has so much more depth than this mere shell of a movie...