The latest film in DreamWorks’ irrepressibly perky and shamelessly Auto-Tuned Trolls series is a synthetic sparkle assault that looks as though it was assembled from the glitter and craft supply section of a well-stocked pound shop. In this, as well as the pick-and-mix greatest hits musical choices and morals, it’s business as usual. The message of this latest round of fizzy pop philosophy stresses the importance of family, along with the usual themes of friendship and finding your voice. A flashback introduces us to the tragic backstory of Branch (Justin Timberlake): he was the youngest member of a boyband, named BroZone, made up of his older brothers. When the band split, so did the fraternal bonds. It’s a peppy sugar rush that should please younger audiences, but the appeal of the series is wearing pretty thin.