Woody Harrelson gives a performance of borderline unwatchable hamminess in this really tiresome film, which sentimentally neutralises parental abuse into a supposedly fascinating angel/devil split. Admittedly, this isn’t as purely insufferable as Viggo Mortensen in the comparably wince-inducing Captain Fantastic. But almost. A radioactive sentimentality oozes from the screen, although it is saved, just a little, by the robustness of Brie Larson’s presence.

The film is based on a bestselling 2005 memoir by US columnist and author Jeannette Walls, about her anarchic upbringing at the hands of an alcoholic, bipolar dad, who always kept his bewildered wife and kids on the move, one step ahead of the debt collectors, rattling all across the country. He is Rex, a brilliant but feckless individual: free-thinker, scientist and engineer, entrancing his trusting and saucer-eyed children with his plans to build them a glass castle of his own design. But his whisky and indiscipline keeps them hungry and confused and often in danger from stove hobs etc. 

Harrelson plays him as a life-affirming wildman, glamorised as a rebel that you hate for his cruelty but of course can’t help loving for his adorable passion. Naomi Watts gets to play his dozy, feather-brained wife, and Larson plays his daughter Jeannette in disillusioned later years, an uptight and controlling career woman who has utterly rejected her dad’s anti-materialism in ways that are intended to suggest that maybe she’s kind of got it wrong and just needs to heal. 

The film is structured in such a way that you consent to an insidious balance: loathing and loving Rex before finally giving him the benefit of the doubt. A rigged game, as Rex himself occasionally rants, and a shallow, treacly piece of work.