“Loving people doesn’t save them” could be the epitaph to the young Canadian director Xavier Dolan’s exuberant, emotionally draining fifth feature Mommy. Its vivid colours, concentrated in an unusual square screen ratio, seem to burst out with devilish energy as we follow the attempts of a loving but stretched mother to look after her 15-year-old son who suffers from attention deficit hyperactivity disorder.

Naturally Sean Penn, earnest Hollywood liberal and hard-working humanitarian, didn't lightly undertake his role as professional hitman Jim Terrier in The Gunman. "The idea of making violence cute – I've never been interested as an actor in those things," Penn has commented. "But when I read this I thought there were a lot of real-world parallels to it."

Susanne Bier follows the disappointing Serena with a well-acted and worthy drama that confronts societal prejudice, the sticky issues around child protection, and our inability to see what's right under our noses. Despite the plot's predictable and manipulative machinations, A Second Chance is rendered compelling every step of the way by Bier's searching direction and a mesmerising lead performance from Game of Thrones' Nikolaj Coster-Waldau.

Saul Dibb dispenses with the first half of Irene Nemirovsky’s great novel Suite Française in about a minute. Grainy newsreel footage disposes of the Fall of France in 1940, then it’s on to the occupation of Bussy, the country town where Lucille (Michelle Williams) falls for gentlemanly German officer Bruno (Matthias Schoenaerts, pictured below with Williams).

Sally Hawkins, Rafe Spall and Eddie Marsan form a super group of supporting actors in this heart-warming British coming-of-age drama which follows an autistic boy on his journey to the International Mathematics Olympiad (IMO).   

The relationship between stars and their fans is symbiotic, but there are barriers for many reasons. Illusions can crumble when the star-struck come too close to their idol. Celebrities have to lead their lives, and intrusions by the obsessed hardly encourage day-to-day routine. Elle L’Adore posits a what-if which takes place when a star decides to breach the barrier.

An innocent is corrupted in South African director Neill's Blomkamp's third feature (co-written with his wife Terri Tatchell), but the kid in question is far from what you'd expect. Set in the near future, it focuses on a reprogrammed police robot with the consciousness, sensitivity and suggestibility of a child - a lovably tatty piece of tech who has been literally labelled a reject, and who sports bunny ears, graffiti and gangster bling.

Adolescence, youth culture and rebellion – often luridly and violently expressed – are the stocks in trade of American director Gregg Araki, who has one of the most distinctive voices in US cinema. But while Araki’s work has tended to exist on the fringe, White Bird In a Blizzard feels like a tiptoe into the mainstream – and the journey seems to have seriously neutered that voice.

We get the big city views of Chicago, the bright lights and the skyscrapers, a few times in Kim Longinotto’s Dreamcatcher, but for the most part we’re planted firmly down at street level, in areas of town probably you wouldn’t want to go to, a fair amount of the time at night. That’s where we first meet the film’s protagonist Brenda Myers-Powell (though I don’t think we ever actually hear her addressed by her surname), who’s cruising the streets, handing out condoms to any prostitute she can find.

Oscar winner Julianne Moore: the phrase has been a long time coming but it finally came true 10 days ago when the actress, long considered one of Hollywood's best and brightest, added an Academy Award to her groaning mantelpiece of trophies for her work in Still Alice. Is this actually the finest performance yet given by the flame-haired 54-year-old? Probably not (Far From Heaven, anyone?), and Still Alice – an entirely well-meaning venture that inspires admiration more than actual affection – is some way from the most memorable movie to yet showcase Moore's gifts.

But as a Columbia University linguistics professor who succumbs to early onset Alzheimer's, the Richard Glatzer-Wash Westmoreland collaboration tells its sorrowful story with sensitivity if no particular inspiration. Let's just say that as a platform for a performer possessed of generally unerring instincts, Still Alice joins the likes of Monster and Blue Sky among the ranks of trophied Oscar titles that will be remembered primarily for their leading ladies. 

The irony of an academic who has given herself over to the study of human language only to watch her command over her own verbal acumen, and much else, fall away in itself feels familiar. Glatzer and Washmoreland clearly love their theatre (Kristen Stewart, cast true to sullen type as one of Moore and husband Alec Baldwin's three children, here plays a budding theatre actress), and some may find echoes in this adaptation of Lisa Genova's novel with the Pulitzer Prize-winning Margaret Edson play Wit, in which an English professor dying of ovarian cancer clings to such works as Donne's "Death, Be Not Proud" even as death comes to claim her. (Stewart and Moore are pictured above)

And it wasn't quite a decade ago that Julie Christie found herself at the Oscars for playing an Alzheimer's patient in Away From Her (in the end losing the prize to Marion Cotillard's Edith Piaf), though Moore's struggle here feels more fearsome moment-by-moment, not least because the Still Alice filmmakers keep their focus on their leading lady, in effect sidelining Baldwin, Stewart, and some fine actors elsewhere in the cast. (Baldwin is clearly a good luck charm when it comes to winning Oscars for his female co-stars: he was Cate Blanchett's husband in her 2014 turn in Blue Jasmine.)

One watches as Alice searches for a word in public or can't find the bathroom within the privacy of her own home, and it's only a shame that the creative team settle for as pat a choice for poetic citation as Elizabeth Bishop's (admittedly wonderful) "One Art", with its opening line, "The art of losing isn't hard to master." We witness the indignities of Alice unable to tie a shoe on the one hand and calling a daughter by the wrong name on the other. You get the inevitable standing ovation moment alongside a worsening chronicle of the illness-induced privations that exist behind closed doors.

The ending, like much else in the film, is overreliant on an extant source, this time on Tony Kushner's Angels in America, the play that budding thesp Stewart happens to have been working on as her mum's recall gives way perhaps for good. But if Still Alice has to borrow rather too often to achieve its effect, the film is lifted by one of the few actresses out there who can make even the blankest of despair feel entirely fresh.

• Read theartsdesk Q&A with Julianne Moore

Overleaf: watch the trailer for Still Alice