Since roughly Flower of my Secret (1995), each new Pedro Almodóvar film has more or less successfully walked the tightrope between an archly camp sensibility and, increasingly, wonderfully elegant formal excellence – both usually yoked together in the service of what might be described as hyper-real melodrama. While his development as a master film-maker may have smoothed off some of the edges that were beloved of his early fans, only a curmudgeon would begrudge him the wider audience and acclaim (Oscars!) that followed, culminating in what are probably his two masterpieces, All About My Mother (1999) and Talk to Her (2002).

But while the cognoscenti have been mechanically acclaiming everything in the last decade, there were hints in his last film, Bad Education (2004) that Pedro had been reading his reviews. Full of postmodern, film-within-a-film jiggery pokery, it lacked the warmth of the preceding films but was pulled back from the brink of sheer self- indulgence by Gael Garcia Bernal’s powerhouse performance. And while Volver doesn’t disappoint, performance-wise, it has the wan feel of a dusted-off screenplay dug out of a bottom draw, half-heartedly filmed now to satisfy a demand for a certain type of middle-brow drama popular with Almodóvar’s international critical fan club.

Working class Raimunda (Penélope Cruz) lives with her husband, Paco, and daughter, in Madrid and visits her Aunt Paula in her native La Mancha. Although Aunt Paula is old and perhaps senile, she insists that she is watched over by Raimunda’s mother, Irene (Carmen Maura), believed to have died years before in a fire in the village. When Aunt Paula herself dies, the truth behind Irene’s disappearance gradually comes to light at the same time as changes in Raimunda’s own life make her reflect on her relationship with both her daughter and her absent mother.

First, the good news. Cruz really is as good as you’ve heard. For anyone whose familiarity with her career begins with Vanilla Sky (2001) and ends with Sahara (2005), she will be a revelation. In fact, she is probably better here than she’s ever been, her superstar status in Spain notwithstanding. Almodóvar surrounds her with wonderful character actresses to share the emotional load, but Cruz is in virtually every scene and is never less than convincing. As is her prosthetic arse, deemed necessary by Almodóvar to both age her a little (Cruz is 32, and Raimunda has a teenage daughter) and further suggest her maternal fulsomeness. Believe me, there’s only going to be one winner in next year’s Best Special Effects Arse category (surely there must be one of those somewhere in the profusion of awards ceremonies?).

The problems lie elsewhere. Intended, I suspect, as something of a fable, the story itself is slight, even trivial. Not in itself a problem, but it is bulked out by diversions that strive for importance but are essentially meaningless, even as they run the risk of unbalancing the whimsical, vaguely supernatural tone. The plot contrivance whereby Raimunda and Paula re-open a recently closed restaurant goes nowhere, and nor does a truly bizarre episode involving Agustina, a middle-aged friend from La Mancha, and her abortive appearance on a Springer-like TV show.

Both of these examples are predicated upon family crises, the former instigated by that old Almodóvar favourite, the feckless and sexually aggressive Heterosexual Male. Paco is the only significant (in screen time terms) male character in the film, and, guess what? He’s a scumbag. Oh, and so was her late father. So let’s see – delinquent father figures? Check. Saintly, full-figured mothers? Check. Crazy but wise older women? Ambivalent comparisons between urban and traditional ways of living?

You get the picture. As professionally crafted as we have come to expect, the film is also Almodóvar’s most formally conservative since… well, ever, probably, which only serves to reinforce the impression of a pedestrian recycling of favourite Pedro tropes. Only towards the end does the film begin to punch its intended emotional weight and you feel you are about to get the pay off. But instead it’s a sucker punch – the film just stops.

I suspect that Volver will be a big hit internationally, following its feting in Cannes this year. It is transgressive enough to flatter liberal sensibilities but without the ambiguity that makes Almodóvar’s best pictures so interesting (I don’t recall any feelings of poetic justice at the fate of the nurse/rapist in Talk to Her). It’s never less than watchable even when it’s preposterous. And it has Cruz. The evening after seeing Volver I was watching TV and caught an advert for a shampoo being promoted by Cruz. Man, she sure does have beautiful hair. And she can rest assured that her performance in the ad is only her second best of the year.

Volver is released in the UK tomorrow.