This is a great film and the visuals that I imagined when reading the book were materialised in the movie which is a huge bonus. Additionally, Viola Davis is the star in my opinion, she plays Dr Gaul brilliantly and is a disturbingly good villain. Definitely worth the watch overall.
However, even though the movie was 2 hours and 30 mins long, they left out some critical details. Yes, it follows the book closely, however it doesn't necessarily explain many of the transitions between scenes, which sometimes appear to be abruptly stuck together and isn't like the smooth flow of the book. Additionally, Tigris is an essential character, I feel like the film didn't show her in as much depth as it should have. These are a few but not exhaustive examples of what was missing in the production.
I watched the film and mistakenly compared it with the original trilogy which I believe did alter my opinion of the film in its own right. These books/movies cannot be compared.