From www.screenrant.com:
"For every great film comes five others trying to replicate its success. Whether it be an R-rated superhero movie, an action blockbuster starring aging actors, a rom-com with converging storylines, or a film about terrorists taking over the White House, Hollywood loves ripping off the thing that worked last time. While oftentimes the uniqueness of the original film is what made it a hit in the first place, that doesn't stop every film studio in the world from blatantly making their own versions of past successes.
But behind every big-budget copycat that at least tries to get it right is a film with a tiny budget, horrible effects, awful actors, and a script that can only be described as ramblings on the inside of a candy wrapper. These films are called mockbusters, and their glorious straight-to-VOD releases capitalize on one thing only: a title that's similar enough to the movie it's ripping off that people will accidentally watch it"