Filmed entirely during the pandemic lockdown in the UK.
The opening scenes of dead bodies in a shopping mall was filmed with a flash-mob of actors who suddenly dropped to the ground with fake severed heads in the middle of the main part of the mall and lay there for several seconds.
The scenes of a deserted post-apocalyptic Manchester city center were real. Filmed during the pandemic lockdown of 2020-2021 all small businesses were closed in the UK during most of the filming and the city's famous trams were not running.
Filmed during winter at -3 degrees Celsius, which made life very uncomfortable for the actress who had to walk around the farm in her nightgown as well as the actors who had to lounge about in beachwear during the "party" scene.
End credits say "In Memoriam Lightning". Lightning was the horse which appears in the opening scene. Sadly, the horse died some time after filming when he was fed a potato by a passer-by in a field where he lived. He made international news as a warning to visitors to the countryside not to feed horses.