The search for a male star who can replace Harrison Ford continues. As the eponymous Valerian, Dane DeHaan is supposed to be a happy-go-lucky, square-jawed hero and roguish galactic agent.

Instead he looks like he should be playing a space cadet in some sort of academy somewhere with fellow cast member Clive Owen as the bullying principal.

Unfamiliar with the comics, I mistakenly thought Valerian and his partner Laureline (Cara Delevingne) were siblings, like a Luke and Leia crime-fighting duo. They’re not – although the French-Belgian Valerian et Laureline comics were a suspected early influence on George Lucas.

Valerian drools over Laureline (more than Luke did Leia) and it quickly gets annoying to watch the little twerp sexually harassing model Delevingne. “He’s got no chance!” I thought.

The romance is worse than Attack of the Clones level space trash, complete with stilted dialogue.

There are hints of Avatar’s Na’vi in the humanoids from the destroyed planet of Mül, who stow away in the bowels of a giant free-floating metropolis called Alpha (the City of a Thousand Planets), where different alien species all pool their knowledge in brilliant harmony. Or not.

There’s a plot involving Alpha’s Commander Clive Owen, the annihilated planet, a kidnapping and a little MacGuffin creature everybody is trying to get their hands on.

At points, both agents get captured and have to save each other. Laureline puts a giant mind-reading jellyfish on her head to find Valerian, who later has to swoop in with a shapeshifting Rihanna to stop Laureline from getting her brains eaten by a race of master chefs on Alpha. (So much for harmony between species!)

The largely teenage audience were probably there for RiRi, but it’s just a cameo really. There’s a rushed immigration subtext involving her character, and the film has a message of love conquering all.

Director Luc Besson has an established reputation for style over substance. Valerian – his passion project – is a zany, hot mess, with the characters slaloming and sloshing around his crazy pinball machine universe. I tried to enjoy it – I loved the score and the soundtrack – I just would have liked better dialogue too.

Valerian is like spending two and a quarter hours (!) on the now-defunct Bubbleworks ride at Chessington. Isn’t it amazing the childhood nightmares that can be dredged up years later?