Might as well cut and paste what I wrote on Facebook a week ago:
As a fan of the comics, it was a mixed bag. To compare it to other franchises, it was very much like the JJ Abrams reboot of Star Trek, but also had some of the aspects of the first live action Astérix movie, where they combined stories, and had scenes "go through the motions" and fall flat.
There were articles in the Francophone press about how Christin and Mézières, the creators of the comic, were behind Besson, and articles in the Anglophone press that saw it as the latest Star Wars ripoff.
One piece of trivia that you would come across in first order is that the title is inspired by the second book, "L'empire des mille planêtes" (Empire of the Thousand Planets), but most of the plot is drawn from the sixth book, "L'ambassadeur des ombres" (Ambassador of the Shadows). I will mainly refer to the latter, so be warned.
Character-wise, the main duo seem to have been written mainly as they were near the end of the series, but in the final act as they were in "L'ambassadeur des ombres". It is also not helped that they are portrayed by actors far too childish for the roles. The back and forth banter works fine for a young Gallic couple, say in their teens or early twenties, but not for Spatio-temporal agents.
The astronef now has its own AI. What point does this really serve? This might also be a good place to talk about the setting. You see, their ship is not only used to travel through space but also through time. This is but one ship of humanity's space-time police patrol, headquartered in Earth's new capital, Galaxity. The brief future-history of the comics is that in 1986, Earth was rocked by a nuclear accident of apocalyptic proportions (not Chernobyl, since this was written back in the late sixties, but that does come back in an ironic way that will not be discussed here) and only recovered from this dark age thanks to the invention of the time machine. Do note that the Spatio-temporal patrol is not one that can rival the power of the Time Lords of Gallifrey. They are but human.
So then, if humanity didn't create "Alpha", then who did? By that, you mean "Point Centrale"/the Centre Point. Which is the point, the main mystery of the place. No one knows, since it's been so long and so many species have joined Point Centrale. Earth, and therefore Galaxity, is a relative newcomer. And it so happens that it's their turn to be the chair of the assembly, their ambassador taking a position similar to secretary general of the United Nations. The Commander in the movie is the Ambassador, and does retain his arrogance. Galaxity does have its imperious side, not only as revealed further in the book, but also in "Bienvenue sur Alflolol" (Welcome on Alflolol), which is kinda where they took the plot of the banished native species returning on a human world. It's still very different from what we see here, though. But this does seem more in line with Besson's similar militaresque caricature from The Fifth Element.
While the Ambassador's goals are more straight forward in the original (just add imperialism to the given duties above and it should be crystal clear), his kidnappers are far more convoluted as they turn out to be a series of puppeteer groups, each one controlled by the next group. This is where one of the mysteries of the book lies, the other being the exploration of Point Centrale and its inhabitants, since it's an barely mapped labyrinth. It's a bit of a shame that they cut out the centaur-like Kamuniks, but kept the equally war-like Bagoulins (whom became a more patriarchal society for some reason). I guess Besson isn't a human polo fan.
Coming back to the main characters, this is a weird choice for a story to adapt, since Valérian spends most of the book kidnapped along with the Ambassador. The book is not the first time that Laureline is the central protagonist or takes over a good chunk of the plot advancement, but it is the classic example for the series. For most of the book, she's followed by a master of protocol that pretty much serves as her comic foil and is a rather pathetic mirror of Valérian. Hmm, that sounds like what I watched. In fact, one of her attempts to locate the two was when she went to get the help of the shapeshifting Suffuss, which of course became Valérian's interaction with "Bubble". So they swapped out the Adonis with Rhianna, equal-opportunity fanservice!
The one thing that Besson did get right on was the portrayal of the Shingouz, that trio of wealth-obsessed information gatherers. The Transmuteur de Bluxte (Converter in English) acts the same, but was given a more macguffin-esque role in the movie (it is simply a hard to capture creature that was given to Laureline to use as the perfect currency exchanger for the labyrinth of Point Centrale), which does bring us to the other main group of aliens and the first act. There are many, many bazaars that the duo visit throughout the series, but the closest to a multi-dimensional raid would probably be "Les Astéroïdes de Shimbalil", and the closest to the actual gimmick would be the space-time "cracker-jacks" that they use at the tail-end of the series. That's definitely the most Besson part of the movie, apart from Valérian being a casa nova. The book and the movie have a superficially similar final act, and so the early appearance of the planet Mûl did perturb me. In a way, this feels like someone blurting out "IT WAS THE SLED!" after the glass ball is dropped.
Basically, while it did have a lot of the visuals of the series, this felt like Besson telling one of his Taxi stories while "going through the motions" of the Valérian comics.