Someday, all US cinema may come to look like this: indifferently shot random events happening to semi-recognisable TV faces. In the case of this smarmily opportunistic Adventures in Babysitting throwback, it's a lip-glossed student (Victoria Justice, this season's Rachael Leigh Cook) obliged to track down her errant kid brother one ker-ay-zee Halloween. Precisely who it's aimed at is anybody's guess: it's preceded by the video for Carly Rae Jepsen's difficult third single, yet persists with smart-arsed, tween-baffling non-jokes about Ruth Bader Ginsburg, mammograms and Alexander Hamilton. As ever, "fun size" translates to "no fun whatsoever".