It's been more than 5 years since I read the book, but I don't remember it being this bad!
The whole movie was so awkward and cringey. The dialogue was weird and stilted, the transitions between scenes were abrupt and made no sense at all, and the overall movie felt like badly written fanfiction (so many things were left unexplained!).
I know the novel wasn't a masterpiece, but this adaptation was absolute garbage. Whoever the screenwriters were, they have no business adapting novels into screenplays. So, so bad.
The actress playing Luce could never have passed for a 17 year old. And both her interactions with Cam and Daniel were so forced and in your face. The scenes where her face was mere inches from one of the guys' faces and they just stared at each other for a full minute without saying anything were so uncomfortable. Like, stop trying so hard to convince us she has chemistry with them. The relationships were overdone to the point that they felt painfully fake and plastic.
Because the screenplay and dialogue were so bad, it made it seem like the actors were terrible. But since I've seen a few of them on other stuff and know for a fact they can, actually, act, I won't criticize that aspect of the movie.
Judging by how bad this movie was, I don't think we'll be getting any more movies from the Fallen saga.