The most surprising thing about The Boss Baby is that it was good. Not just a child-friendly home run with enough fart jokes and visual gags to pass kids’ time, its themes of sibling rivalry, parental love and the nature of family relationships made for a genuinely moving – if uniquely absurd – comedy-caper. Of course, that was helped by its basis in 2007’s picture book bestseller of the same name by Marla Frazee, which ingeniously posed the conflicts of a new sibling with that of a mover-and-shaker CEO coming in to reshape a company.

Never mind that The Boss Baby was, for all its charm, not much more than an expression of what Toy Story was really about. With Andy’s devotion to Woody challenged by the arrival of Buzz Lightyear, the Tim Allen-voiced space ranger was the original Boss Baby. By throwing out the subtext with the bathwater, The Boss Baby made its intentions clear to parents and kids alike – and grossed more than $500 million worldwide in the process.

The Boss Baby 2, which gets the addendum “Family Business” in its US title, has no such smarts or cross-generational appeal. A “soulless cash grab” in the same way Men In Black 2 and the other most underwhelming sequels of recent years have been (according to Rick Sanchez at least), it totally fails to live up to the first movie’s glimmer of promise.

Director and co-writer Tom McGrath pulls a reverse Back to the Future, with dad Tim (James Marsden, replacing Tobey Maguire) becoming a toddler so he can spy on distant daughter Tabitha (Ariana Greenblatt). This narrative choice is compelling for a scene or two, and it’s easy to see why McGrath and writer Michael McCullers went for it. Meanwhile, the titular Boss Baby (still Alec Baldwin, thankfully) and Tim’s younger daughter Tina (Amy Sedaris) investigate shadowy entrepreneur Erwin Armstrong (Jeff Goldblum).

Yet The Boss Baby 2 makes the fatal error of putting all its emotional eggs in the grown-up basket. Parents in the kid-friendly screening I attended appeared charmed by the Tim-Tabitha plot, but youngsters became restless. Laughs were few among audience members who, it’s fair to say, tend to be a little more generous than their cynical mums and dads. McGrath seems to know this, banking on a colourful explosion of a final act which doesn’t make much sense, frankly, but should pay back children’s investment in the film so far.

That might make for a pleasant moviegoing experience. It certainly doesn’t make for a good movie. The Boss Baby 2 has some pressure in following an inexplicably entertaining first film, but it fails to birth anything more than a semi-mindless slog.