I wanted to like this film. I really did. As a fan of the Fifth Element, I was expecting to find a well-developed plot, kitchy humor, memorable characters, and over-the-top action sequences. It had the action, but no soul. Neither of the two main characters had the acting chops to carry a scene, even the 'witty' banter came of scripted and flat as if Ben Stein had taken a heavy dose of lithium and stumble on set. The story also had several faux pas, including adding characters to advance parts of the story, only to kill them off a few minutes later.
The characters were flat and shallow. Valerian, the title character and the story's protagonist, was just plain not likable. He warranted no emotional investment. Instead of holding on to my seat in the big action sequences that threatened death and dismemberment, I felt myself not caring whether he lived or died. Part of this was due to the fact that he had the emotional range of a piece of plywood (think Hayden Christensen in Star Wars). I couldn't tell if he was professing his undying love or ordering a burger and fries at McDonalds.
The main bad-guy, who is exactly who you think it is from the get- go, also warrants no emotional investment, especially considering he spends most of the movie is some sort of stasis. The reason to hate him is only revealed near the end of the movie in a flashback sequence, and I never knew enough about his character to even form an opinion about him. When he is finally defeated, you can barely marshal a shrug, because, once again, you just don't know enough about him to care.
Rihanna's character, who by-the-way had a beautiful introduction sequence, is another example of this shallow character building. Our hero finds himself needing to access an inaccessible area that only Rihanna can provide access to. Naturally he finds himself in a strip-club where he recruits her to help him through this, which she does, only to have her die WITHIN MINUTES of fulfilling her end. Her death sequence, which, judging by the musical score, was intended to be an emotional scene, falls on the side of apathy. We never knew enough about her character to care when/if she died. There was not enough time to build that emotional investment.
There were many other eye-rolling moments, including a direct rip from The Taken script and an alien who vows unrelenting vengeance only to NEVER SHOW UP IN THE MOVIE AGAIN, but they are much too numerous to list. All-in-all, Valerian was at best a lackluster movie experience that fell in the same trap that many big-budget films do: rely on over-the-top special effects to mask shoddy story telling and flat characters. Save your money for the red-box rental.