Screenwriters Peter Baynham and Sarah Smith have programmed this watchable if very derivative animated movie about a lonely, bullied kid’s malfunctioning robot best friend: a cheeky tech spin on ET, with some borrowings from the Disney feature Big Hero 6 and the Pixar meisterwerk Wall-E. It’s entertaining, though composed with algorithmic precision, and it winds up suspiciously neutral about whether kids really should abandon digital enslavement in favour of real-life human friends.

Barney (voiced by Jack Dylan Grazer) is from a poor Bulgarian-immigrant family in small-town America. His dad, Graham (Ed Helms), is a sad widower, scraping a living selling novelties over the web, and his comedy Borat-gran Donka (Olivia Colman) keeps goats and chickens. Barney is deeply ashamed of his poverty, his asthma and his failure to fit in: he is regularly forced to sit on the school’s “buddy bench” during recess by the well-meaning teacher, begging for people to hang out with him.

Above all, Barney is ashamed that his family can’t afford to buy him a B-Bot, the new must-have toy: a waist-high, R2-D2-shaped robot that follows you around, hooks you up to social media, records video, plays games, and knows all your tastes and hobbies. These gizmos are marketed by the Bubble corporation, run by twentysomething ex-nerd Marc (Justice Smith), who believes the B-Bots will help kids make friends. Marc’s senior partner and majority investor is the coldly calculating Andrew Morris (Rob Delaney), who, we are given to understand, is the corporate bad guy – as opposed to Marc being the corporate good guy. That neutrality again.

Poor Barney’s humiliation and wretchedness reach a low point when his dad buys him a damaged B-Bot that fell off the truck, because it’s all he can afford – a B-Bot that boots up incorrectly (with the old dial-up sound) and is all wonky and wrong. But this dodgy B-Bot, Ron (Zach Galifianakis), turns out to be wildly good fun with its hilariously inappropriate behaviour – and it beats up the bullies. The corporation wants to reclaim this rogue unit, so Barney has to hide his wonderful new best friend.

The movie runs with touch-screen efficiency and there are some genuinely tender moments when Barney is brought face-to-face with his own misery. When Ron hears that Barney doesn’t have a mother, he says thoughtfully: “She was returned to the factory?” Barney himself, with his short hair and big ears, looks poignantly, if perhaps unintentionally, like the kid on the front of Mad magazine.

The film is ultimately faced with a dilemma – should Ron finally “go home” in the ET sense, having done his job by teaching Barney and all his basically good-hearted friends to do without these expensive, soulless toys? Or should all the mean-girl and mean-boy B-Bots be reprogrammed to be like nice, lovable Ron? (But wait: wasn’t the whole point that real friendship has nothing to do with narcissistic tech gadgetry?) Well, the movie never quite settles that question, although Baynham and Smith would be entitled to point out that digital tech and social media are here to stay and a movie that earnestly rejected them on young people’s behalf wouldn’t be realistic.

This is a good-natured film that works best in its opening act – when Barney himself is the substandard robot, whose software somehow makes him unacceptable in the world.

• Ron’s Gone Wrong screened at the BFI London Film Festival, and is released on 15 October in the UK, 21 October in Australia, and 22 October in the US.