I'm a big fan of Assayas' previous films, so this one was a real let-down. Here's a few reasons why (SPOILERS):
1. It had no clear POV. By following so many characters simultaneously, it resulted in no emotional involvement with any of them.
2. The film had no center. It felt like a series of random scenes strung together by an editor. With no forward momentum driving it, it was really dull.
3. This period in history is one of my favorites, and one which I've researched quite assiduously since college. In fact, I've always regretted I was too young to have been part of it. That said, I should have loved this film. But, the fatal mistake Assayas made was in not showing WHY these kids were so pissed off. Did one of them lose a brother or father in Vietnam when the French were there a decade or more earlier? Were the officials at the school perpetrating Fascist tactics upon the students, which resulted in their vandalizing the school and nearly killing a security guard? And so on.
As it was presented, they just came off as a bunch of entitled bourgeois brats who were being anarchists because that's what was fashionable at the time. Ten years later if they'd been part of my generation, they'd have had short hair and been preppies. There was no clear ideology driving them and no clear motivation driving the story. Therefore, there was nothing for me as an audience member to invest in.
Hopefully another filmmaker will choose to tell a story about this turbulent, fascinating time in history when the world's young people had a conscience and believed ideas and ideals were worth fighting for. This one ain't it.