Film reviews: Kung Fu Panda 2 | Mother's Day | Sweetgrass | A Screaming Man | Kaboom

Our film critic reviews the best and worst of this week's new releases...

Kung Fu Panda 2 (PG) **

Directed by: Jennifer Yuh

Voices: Jack Black, Gary Oldman, Angelina Jolie, Dustin Hoffman

The first Kung Fu Panda struggled to deliver on the brilliance of its titular high concept thanks to slack writing, predictable plotting and anonymous A-list vocal performances. It did, however, generate enough silly money at the box office to make a sequel inevitable. Hence Kung Fu Panda 2, which offers more of the same, even though it tries to convince us it doesn't. Wise to the ways in which the Toy Story sequels deepened the emotional journeys of their characters, the film tries to add a little "who am I?" existential angst to the plight of its jelly-bellied ursine hero by having Po (Jack Black) embark on a quest to find out what happened to his real parents after finally twigging that the dumpling-cooking goose who raised him may not be his biological father. Alas, having failed to lay the groundwork with solid characters first time round (see previous sentence), the film's attempt to retrofit our hero with psychological complexity merely makes its repetitive plot – revolving around Po confronting his destiny in the form of an evil peacock (Gary Oldman) intent on taking over China with a kung fu-killing cannon – seem as hollow as bamboo.

Mother's Day (18) ***

Directed by: Darren Lynn Bousman

Starring: Rebecca De Mornay, Jaime King, Shawn Ashmore

Legendary z-grade production house Troma isn't known for making classic genre films, even accidental classics, but its 1980 slasher film Mother's Day has provided the gruel for this surprisingly effective little shocker. Rebecca De Mornay channels her psycho nanny from The Hand that Rocks the Cradle to play the sociopathic matriarch of a bunch of homicidal bank robbers who take refuge in the family home after a bungled job results in one of them being shot in the stomach. Unfortunately, upon arrival they realise the house is no longer their family home, but that of a middle class couple who snapped it up a few months earlier and are in the midst of a cosy house-warming party. That's the cue for director Darren Lynn Bousman (Saw II-IV) to transform the film into a gnarly home invasion thriller and he makes good use of these early plot turns to change the parameters of the story. Effective performances from his cast help up the stakes too, particularly as the hostages begin to reveal their atavistic sides. It doesn't all work (some of the reasons preventing the hostages escaping are a bit too convenient), but it's still better than it has any right to be.

Sweetgrass (15) ****

Directed by: Ilisa Barbash, Lucien Castaing-Taylor

The gentle, low-key observational style of this beautiful and absorbing documentary may initially belie the sheer effort that goes into driving some 3000 sheep through the mountains of Montana and Wyoming, but by the movie's end you'll be left in little doubt about why this is a vanishing way of life. The film took more than eight years to complete, the bulk of its material shot in 2001 as Montana rancher Lawrence Allested became the last man to keep alive the century-old tradition of herding sheep 150 miles through the Absaroka-Beartooth Mountains for summer pasture. With no external narrative or score, little in the way of commentary, and lots of languorous shots of sheep going about their business, the film makes it easy to get lost in contemplation at the wonder of the wilderness, but as it progresses it begins to strike a subtly elegiac, unsentimental tone that pays testimony to the back-breaking work involved in maintaining this tradition and simultaneously laments the inevitability of its passing in the modern world. The sheep, meanwhile, may rival the goats of La Quattro Volte for the title of the year's most compelling cast.

A Screaming Man (PG) ****

Directed by: Mahamat-Saleh Haroun

Starring: Youssouf Djaoro, Dioucounda Koma, Hadje Fatime N'Goua

French-based Chadian film-maker Mahamat-Saleh Haroun (Abouna, Daratt) returns once more to his native country to explore the devastating impact that ongoing political tensions and violent insurgencies have had on the population over the past four decades with this moving, regret-filled drama. Carefully fusing the political and the personal via a tale of generational warfare, the film revolves around the ageing Adam (Youssouf Djaoro) and his grown-up son Abdel (Dioucounda Koma). Both work as poolside attendants at a hotel, a job in which Adam, a former swimming champion, takes genuine pride. When economic realities result in Adam being demoted, he engineers a return to his former position that will have fateful consequences for Abdel that Adam can't even begin to comprehend. What follows is an unfussy parable about the ways in which confusion and self-interest can have terrible consequences. Structuring and pacing the film to reflect the rhythms of daily life, Haroun shows not only how external chaos can impinge upon it, but also how Adam's passive avoidance of the surrounding madness over the years has warped his moral core, making him receptive to the craziness when it does eventually affect him directly. It's a quietly devastating film, aided greatly by a haunting performance from Djaoro.

Kaboom (15) ***

Directed by: Gregg Araki

Starring: Thomas Dekker, Haley Bennett, Juno Temple, Chris Zylka

After accidentally revealing his mature side with 2005's thoughtful, haunting and sophisticated coming-of-age drama Mysterious Skin, director Gregg Araki fully reverts to the self-indulgent, in-your-face posturing of his early 1990s output with Kaboom. Like Totally F***ed Up and The Doom Generation, Kaboom is deliberately garish in style and forthright in attitude, serving up a dreamy fantasy of college life that satirises and adopts the tropes of science fiction and detective films to explore the identity issues of a group of sexually polymorphous students. Chief among these is Smith (Thomas Dekker) a film studies student haunted by apocalyptic dreams which may or may not have something to do with his dead father, a factor that comes more into play with the arrival in his life of London (Juno Temple), a liberated girl with an emotion-free attitude towards sex. There's also Smith's best friend Stella (Haley Bennett), suffering the after-effects of dating a vengeful witch who hasn't taken kindly to being dumped. It's the kind of film that refuses to draw lines between what's real and what's hallucination, just as the characters resist defining their identity by sexual orientation.