Rock of Ages, Adam Shankman, 125 mins (12A) Polisse, Maiwenn, 127 mins (15) A Royal Affair, Nicolaj Arcei, 128 mins, 15)

What happens when Tom wigs out? Not much sex, no drugs and naff-all rock'n'roll

You don't expect a musical built on a foundation of naff 1980s glam-metal anthems to be a masterpiece. What you do expect is that it might be fun. As long as it offers some camp, singalong entertainment then it will have served its purpose. Rock of Ages doesn't.

It's set in 1987, in a live-music venue on Los Angeles' Sunset Strip. The mayor's wife, Catherine Zeta-Jones, is campaigning to have the premises closed down, but the club's future might just be secured if an unreliable rock star, Tom Cruise, deigns to perform there. It struck me that it might have been simpler for all concerned if someone had just invited Zeta-Jones to have a look around. What she'd have found is a club where nobody smokes and where drugs are never even mentioned, just up the road from a strip joint in which the performers all keep their clothes on. Rock'n'roll, it ain't.

There's some sex and drinking going on, but most of the film is wasted on an anodyne romance between two wholesome bar staff, Julianne Hough and Diego Boneta. Between their earnest soul-searching, the half-witted dialogue, the drab design and the workaday choreography, any pizzazz the songs might have is crushed into oblivion. Alec Baldwin and Russell Brand have some amusing interplay as the club's managers, even if Brand has invented a weird new Birming-pudlian accent. But essentially all Rock of Ages has to recommend it is Cruise's out-there cameo as a frazzled rock god who's always three-quarters of the way through a bottle of Scotch. Anyone who sees the film would be advised to be in the same condition.

There's a lot more humour in Polisse – and it's a drama about Paris's Child Protection Unit. Barrelling along with the authenticity of a fly-on-the-wall documentary, it doesn't have a plot, just a series of cases involving child molesters, pickpockets and abducted babies, intercut with snapshots of the officers' complicated home lives.

It's frank about the harrowing crimes they contend with, and the unbearable pressure such crimes place upon them, but that makes its willingness to be funny all the more laudable. The characters squeal with glee when they switch on the siren in their police car, and they fall about laughing when a teenager lists the sexual favours she traded for a mobile phone. "Well," she argues, "it was a smartphone."

A Royal Affair may have the generic title of a television movie about Charles and Camilla, but in fact this rich, intelligent and moving Danish period drama deserves to be ranked alongside Amadeus and Dangerous Liaisons. It's the true story of a German doctor, Johann Friedrich Struensee (Mads Mikkelsen), who ministers to the mentally fragile King Christian VII (Mikkel Boe Foelsgaard) and has an affair with Queen Caroline (Alicia Vikander) in late 18th-century Copenhagen. But it's as much about social reform as bodice-ripping. Struensee is determined to impose Enlightenment ideas on Denmark, but a cabal of aristocrats is aghast at the very thought of outlawing torture or vaccinating the populace against smallpox, so they use Struensee's romance with the Queen against him.

Critic's choice

American horror prodigy Ti West offers The Innkeepers, inspired by the hotel where he shot it, and with more character quirks than shocks in an alluring garage-sale answer to The Shining. The London Indian Festival kicks off with the epic Gangs of Wasseypur, fresh from Cannes and hailed as India's answer to The Godfather. (www.londonfilmfestival.co.uk)