One of the films that appear in the TV while the people in the bar look for the news is William Castle's House on Haunted Hill (1959), a film in which strangers are trapped in a (supposedly) haunted house. In The Bar, the strangers are trapped in a bar. Another coincidence is the number of people: in The Bar, there are nine people inside the building. In House on Hauted Hill, there are five guests, but counting the hosts and servants, there are also nine people inside the building.
After their first collaboration together in The Day of the Beast (1995), is the first Álex de la Iglesia's movie filmed in Spain in which Manuel Tallafé doesn't appear.
Its original release date was January 20 2017. After be selected in some festivals, was delayed to March 24 2017.
When Israel puts coins (and a paper origami boat) on the deceased, he is making a reference to an early form of bereavement practice from Greek and Roman mythology about "Charon" or "Kharon", a ferryman who carries souls of the newly deceased across the river to the afterlife. A coin to pay Charon for passage was sometimes placed in or on the mouth or on the eyes of a dead person; if the dead did not pay, they were condemned to wander the earth as ghosts.