A South African tweenager slowly pulling tongues at the camera in Paul Taylor's We Are Together will be one of this critic's enduring images of 2008. It's not a rude gesture, but a charming sign of the growing confidence that Slidile Moya feels in dealing with the world outside the Agape hostel where she lives with 25 other children from KwaZulu Natal, who have been left orphaned by the country's wholly avoidable Aids epidemic.

In fact, Slidile is one of the lucky ones, as she is not only doted on by the centre's founder, 'Grandma' Zodwa Mqadi, but she is also a member of a choir that has been invited to Britain on a fund-raising trip. Furthermore, her older siblings also live nearby and they are allowed regular visits home.

But, life being what it is, the tour is cancelled, Slidile's brother, Sifiso, succumbs to the virus that killed their parents and Agape burns down because of faulty wiring. Yet Slidile and her sisters face these trials with a humbling forbearance that makes their collaboration on a CD with local pop star Zwai and their appearance on a New York stage with Paul Simon and Alicia Keys all the more moving.

Taylor deserves credit for recording the disease and deprivation he witnesses without melodramatising either. But it's the dignity he affords the dying and the solidarity he shows the Moya sisters that makes this such an authentic and evocative documentary. Hence, Slidile's affectionate tongue pull when he teases her about being starstruck at duetting with Zwai on Oh Happy Day in a big-city recording studio.

The passing of childhood innocence is also the them of Céline Sciamma's debut, Water Lilies. Set in the Parisian suburb of Cergy, this is a delightful insight into the awkwardness of adolescence and the exquisite agony of first love. What's more, the spirit of Esther Williams seeps through the story of sullen waif Pauline Acquart's crush on synchronised swimming star Adèle Haenel.

However, Sciamma slyly reveals that what looks graceful on the surface can often disguise hidden gaucheries, as she contrasts the blonde Haenel's insecurities with the self-possession of Acquart's podgy pal Louise Blachère, who is desperate to sleep with Haenel's hunk boyfriend. With moments of playful immaturity tempering the perceptive exploration of sexual identity, this is beautifully played and delicately staged. Moreover, it depicts 15-year-olds as nascent adults without patronising or demonising them, which is something European cinema consistently does better than Hollywood.

Unfortunately, the week's other aquatic offering is less accomplished and this is because the Hungarian drama Children of Glory has its eye as much on appealing to the international market as on satisfying a domestic audience that wouldn't have needed quite so much History 101 exposition. Director Krisztina Goda simply fails to keep a lid on the melodramatics scripted for her by Eva Gardos and Joe Eszterhas, who allows all the bad habits he picked up in Hollywood to spoil what should have been a compelling and provocative account of the 1956 Hungarian uprising that was suppressed by the Soviets after the West had been distracted by the Suez Crisis.

Thus, instead of being integrated into an in-depth discussion of clashing ideologies, water polo star Iván Fenyö's whirlwind romance with freedom fighter Kata Dobó feels like something out of a penny dreadful, as they periodically break off from love making either to battle their way out of yet another momentous event or to engage in dinner-table squabbles with his over-protective mother. Moreover, the massive significance of the showdown between the Hungarians and Soviets in the water polo semi-finals at the Melbourne Olympics is ruinously undermined as Goda intercuts between the bloodbath in the pool to Dobó's drawn-out interrogation by the secret police. Some of the street-fighting sequences are suitably pitiless. But this essentially represents a wasted opportunity to alert the wider world to a courageous nation's tragic betrayal.