Valerian and the City of a Thousand Planets opens with great promise. Beginning with news footage from a space mission in 1975, we travel through time to the strains of Bowie’s “Space Oddity” into future centuries, the International Space Station becoming a global then intergalactic hub of alien-human goodwill and co-operation.

Each national then interplanetary addition adds to the space-station until its mass proves more than the Earth’s orbit can handle, necessitating that the whole ungainly structure, now named Alpha, take its chances in the interstellar currents of outer space.

Besson has spared no expense in the creation of this universe. Based on a French comic book series of the late 1960s, Valerian and Laureline, the film is a dazzling spectacle of imagination and computer-generated artistry, all enriched by the 3D format.

The plot bowls along as government agent Valerian (Dane DeHaan) and his partner Laureline (Cara Delevingne) bounce from one episodic adventure to the next, all featuring a stupefying array of environments and alien characters.  It’s an understatement to say there’s a lot going on.

Valerian and Laureline are on the trail of a military conspiracy to cover up the annihilation of an eye-rollingly peaceful species known as Pearls, who are reminiscent of the Na’vi of Avatar but with nacreous, iridescent skin.

Then there’s the sub-plot of the relationship between the protagonists and a weirdly timed marriage proposal.

In stark contrast with the rich profusion of alien creatures and habitats, the human characters feel disappointingly wooden. Valerian’s self-confidence comes across as smug arrogance and the barely-an-adult DeHaan feels poorly cast as both a charming rogue and a Major in the military. Delevingne is only minimally more believable as the assertive Sergeant Laureline and the complete lack of chemistry between the two makes their romantic banter fluctuate between uncomfortable and cringeworthy.

This film is so full of stylish creativity that it is almost overwhelming and Besson tantalises us with a parade of fleeting glimpses of fascinating alien life-forms and civilisations. At one point, Valerian crashes through numerous walls separating Alpha’s diverse sectors and as he charges through each one you just want the film to slow down and take a moment to appreciate the richness of imagination that has gone into creating this world that we have sped through in mere seconds.

As a fan of Besson’s work and someone who considered The Fifth Element to be a dazzling example of sci-fi cinema, I truly wanted to love this film. There is much to appreciate and it is undeniable that Besson’s vision and commitment to universe creation is unparalleled.

Despite all misgivings about the human actors, I suspect that if I had seen Valerian and the City of a Thousand Planets as a teenager I would’ve been just as overwhelmed as I remember being when watching The Fifth Element for the first time, way back in 1997.