As just a movie? I thought it was beautifully made and showcased the struggles characters were going through with grief, mental health disorders like bipolar disorder, depression, etc. It made me sob. The casting was well-done It felt very real, in the sense that the characters were real people, with real feelings, with real wants and needs, I didn't find as many tropes or annoyingly common elements as one might expect.
Now, as for the authenticity to the book: (This is the part with spoilers, you've been warned) That's why I docked a couple stars.
There are a number of things I, as someone who had read the book and knew some niche details, found disappointing were not included in the movie, like:
1. Finch and Violet don't meet at the bell tower, they meet at the bridge. I found this weird because yes while the bridge is an important location to the story, the bell tower is too, and (also in the movie) it doesn't happen during the school day and they do not find each other, rather, Finch is running and finds Violet. (I thought this was particularly odd because Finch being up there meant something too, it's not just about Violet's grief in the beginning.) This is the one I found most disappointing because it's kind of a pivotal moment - who saves who? This creates the need both characters have for each other. In the movie it's clear that Finch saves Violet.
2. When Finch asks Violet to be his partner for the project, in the book it is in class, in one scene, but social media gets involved in the movie and it happens in an evening. This was confusing to me, but it makes more sense than some of the others because the movie was a modernized version.
As well as some smaller more nitpicky things:
3. On Finch's final disappearance, he does not leave an elaborate trail for Violet to follow, which I really enjoyed seeing unfold in the book.
4. Finch and Violet do not use Facebook in the movie (Yes, again, this was probably omitted because it got modernized)
5. Finch and Violet do not sleep in the closet in the movie
6. There is no Ryan Cross, only Roamer, who still kind of makes moves on Violet but not as much as Ryan did in the book
7. There are no scenes with Finch's dad in the movie (Why? He was an important character in the book, caused Finch to grow a lot + struggle)
8. It felt very rushed in the movie - In the book it was a lot of a slow burn: Violet didn't really fall for Finch until the end and then her parents got involved and it was a whole thing, in the movie it's like: wanders, accidentally spent the night, parents find out, he disappears. Sad.
9. No Germ magazine. (Again, why? It symbolizes Violet's growth and would've added a lot to the movie)
All of these baffle me, because I can't tell why they were so hard to include, especially, especially especially considering the author was one of the screenwriters! I just think it could've been done better.
Despite all of these things, it tells a story, an important story. Should you watch it? Yes, if the story is important to you. Even if it's not, it can't hurt. But, if you've read the book, will you be disappointed? Probably.