It's not news to say that Hollywood relies ever more heavily on familiarity and nostalgia. But the nostalgia is getting stranger, generating movies that can seem less like products of the human mind than of some artificial intelligence gone awry. Such is Pokemon: Detective Pikachu, based on the 2016 computer game. It's set in the vaguely futuristic Ryme City, where humans and Pokemon live in harmony according to the principles of benevolent zillionaire Howard Clifford (Bill Nighy). Beneath PIkachu's cuddly exterior beats the heart of a hardboiled police detective, as the film's 21-year-old human hero Tim Goodman (Justice Smith) learns when he arrives in the wake of the apparent death of his father Harry, Pikachu's partner on the force. Detective Pikachu is bizarre and familiar, but even within the familiarity there are a few surprises. Detective Pikachu genuinely qualifies as family entertainment which parents and children can watch together and both might enjoy.