HAVANA — The day after Havana is invaded by the living dead, Juan and Sara emerge from their dilapidated apartment building to find the streets filled with people roving aimlessly, their wide eyes blank.

“It all looks the same to me,” Sara shrugs.

The suggestion that 52 years of socialist rule have turned Cuba into a zombie state, a central conceit of the new Cuban horror spoof “Juan of the Dead,” is daringly irreverent satire in a country that takes its revolution with deadly seriousness.

But instead of being forced underground, the movie was included in an officially sanctioned film festival last week where Cubans flocked to see it in such numbers that the police had to intervene and extra screenings were added. Its camp humor notwithstanding, this crude, low-budget splatter film has become an improbable landmark in the gradual opening of Cuban culture.

“Cinema reflects what’s going on around us,” said Carlos Hernandez, 47, a street performer who was among the 1,300 people in the audience at a screening on Thursday. “There are openings. The walls around what you can and can’t say are starting to crumble.