Darren Hughes’s review published on Letterboxd:
I feel many will see this as a typical, shallow, angsty teen story with characters constructed solely to serve the first world problems of their middle class upbringing. It is far from that and whilst there is a lot crammed in to its 100 minutes, there is value and consolation in the way it deals with the issues particularly to those who have ever been put in any of the situations depicted as a young adult. Not every film about these topics needs to be thoroughly miserable to be valid.
From what I gather from summaries, the changes from the book serve to only ground the story further.