Eighteen contenders are in the running for the coveted Palme d'Or gong for best picture, but unlike previous races, no obvious winner emerged during the 12-day event in this French Riviera resort.

"Two years ago 'Amour' crushed everything in sight, last year 'Blue is the Warmest Colour' crushed everything in sight," Jean-Philippe Guerand of Film Francais magazine told AFP, referring to the last two winners.

"This time around there are no such overpowering films," he added, looking to a nailbiter finish at the world's biggest cinema showcase.

Trade magazine Variety predicted Andrey Zvyagintsev's "Leviathan", a searing attack on abuse of power in contemporary Russia which has already run afoul of the country's culture minister, would take home the main prize.

Its chief critic Justin Chang noted that the film's ripped-from-the-headlines relevance coupled with its dramatic power made it a good bet to win the favour of the jury led by New Zealand director Jane Campion.

Audiences also swooned over Canadian wunderkind Xavier Dolan's audacious drama laced with wicked humour, "Mommy". He would, at 25, become the second youngest Cannes winner ever, just behind Louis Malle.

The film's star Anne Dorval, playing a feisty woman grappling with a violent, bipolar son, is also a favourite for the best actress prize.

US movie website Indiewire called the picture "amazingly alive" and "one of the most vibrant, intoxicating, illuminating films of this or any Cannes".

Germany's daily Sueddeutsche Zeitung hailed Dolan as a "wunderkind" and a worthy successor to the late iconoclast Rainer Werner Fassbinder.

Reviewers also embraced "Two Days, One Night" by Jean-Pierre and Luc Dardenne of Belgium, starring Oscar winner Marion Cotillard as a suicidal woman forced to fight to save her job.

It would be the naturalistic filmmakers' third Palme d'Or, a Cannes record, after "Rosetta" in 1999 and "The Child" in 2005.

Cotillard appeared on many shortlists for acting honours, along with Julianne Moore for her role as a panicked ageing film star in David Cronenberg's biting Hollywood satire "Maps to the Stars".

"Winter Sleep" by Turkey's Nuri Bilge Ceylan, which he co-wrote with his actress wife Ebru, mesmerised cinema-goers — despite its three-hour-plus length — with a domestic drama between a wealthy retired actor and his beautiful, frustrated wife.

Britain's Mike Leigh, who won Cannes in 1996 for "Secrets and Lies", drew cheers for the biopic "Mr Turner".

The lush historical portrait of iconic 19th century painter JMW Turner features a grunting, snorting, spitting, womanising warts-and-all performance by Timothy Spall, a character actor best known as Peter Pettigrew in the Harry Potter movies.

"Foxcatcher", the latest feature from Bennett Miller, the director of "Capote" and "Moneyball", proved a midweek delight for what was called an "astonishing" performance by comic Steve Carell.

The true-crime story depicts the murder of an Olympic wrestling medallist by chemicals fortune heir John du Pont. Carell is nearly unrecognisable in the role, which was already generating Oscar buzz.

"Timbuktu" by Abderrahmane Sissako won fans as a moving, visually striking first feature about the defiance jihadists encountered when they briefly took over northern Mali.

And "Wild Tales", an Argentine collection of uproarious revenge fantasies, made a splash for up-and-coming director Damian Szifron.

Meanwhile "Adieu au Langage", a 3D extravaganza by New Wave legend Jean-Luc Godard, featuring a frenetic patchwork of images, musings, white noise and music clips, baffled many but sent some critics into raptures.

Manohla Dargis of the New York Times called it "a thrilling cinematic experience that nearly levitated the packed 2,300-seat Lumiere theater".

Some of the most hotly tipped features at the festival, however, fell flattest.

The opening night, out-of-competition film, "Grace of Monaco", starring Nicole Kidman as the Hollywood-darling-turned-European-princess was mercilessly savaged by critics.

The appearance of Canadian heartthrob Ryan Gosling delighted fans massed on Cannes' seaside main drag, the Croisette, but his directorial debut "Lost River" was blasted as "dumb-foundingly poor".

And new releases by the Oscar-winning director of "The Artist", Michel Hazanavicius, and Canada's Atom Egoyan landed with a thud.

The festival ends Sunday with screenings of this year's highlights