'Hunger is the most genuine motivation,' says one of the protagonists in Look for a Star during a scene in which the film's main characters chatter about their craving for life's culinary pleasures.

Spin the comment around, however, and it serves as a handy metaphor which explains the vacuity of Andrew Lau Wai-keung's romance drama: with its plotlines offering merely a cursory glimpse of the difficulties of relationships spanning class differences, Look for a Star is flat and unengaging, its views on love expressed with a smirk rather than a smile.

This outlook is best summed up by the efforts of the film's star, Andy Lau Tak-wai. He has played frivolous playboys before - most famously in 2000's Needing You - but his turn here as the jet-setting, casino-owning tycoon Sam offers only a glimpse of an emotionally complex soul.

Oozing ironic detachment, Sam is played as if it were impossible he would hanker after anything, something which undermines his determination to woo someone below his social station.

Playing Sam's object of affection, Shu Qi (above right with Lau) gives a much more nuanced turn as Milan, the lowly Macanese croupier-cum-dancer struggling to cope with the pressures of being a rich man's courtesan.

Her humiliation is complete when Sam's mother (Rebecca Pan De-hua) demands the pair sign a pre-nuptial agreement - a clear sign of the undignified, slippery slope Milan has to scale in her part of a terribly skewed deal.

This is not to mention, of course, a hackneyed plot device which showcases the gaping chasm between the pair: Sam - who owns the hotel where Milan works - is the property magnate who bought the land where the theatre housing Milan's cabaret troupe was built.

Mirroring the on-off relationship between Sam and Milan are two subplots revolving around budding relationships built on similarly shaky foundations. There's the romance between Jo (Denise Ho Wan-sze), Sam's classy assistant who harbours a near-comic anxiety about her feminine qualities, and Lin Jiu (Zhang Hanyu), a modest labourer working in Sam's hotel; there's also the troubled courtship between Tim (Dominic Lam Ka-wah), Sam's chauvinist confidant-cum-chauffeur, and Shannon (Zhang Xinyi), an independent-minded, self-sufficient single mother.

Look for a Star would have been more substantial if these two pairings were given more air time, so as to offer two other ways to probe class antagonism and gender perceptions in personal relationships. With the bulk of screen time dedicated to the storyline between Sam and Milan, however, the break-up and make-up of Jo, Lin Jiu, Tim and Shannon are left vague and the possibilities of interesting anecdotes are quashed.

What is left burning in the mind is the wide variety of product placements which pepper Lau's film, from casinos to beef jerky, not to mention the tourist-brochure imagery of Macau.

Look for a Star is screening now