Trivia: The final film starring Bruce Willis to be released, coming out almost exactly one year after he announced his retirement due to Frontotemporal Dementia (initially diagnosed as Aphasia). Like many of his final films, it was created primarily for the VOD, streaming and home-video market, but was also given a token limited release in certain overseas markets.
Trivia: Sylvester Stallone originally exited this film in 2017 over creative differences with producer Avi Lerner. Arnold Schwarzenegger exited as well in solidarity with Stallone. The film ended up being shelved for several years until Stallone returned, albeit in a much smaller and final role. Schwarzenegger, as well as other key actors from the franchise, ultimately did not return.
Trivia: Zack Snyder originally intended for the movie to be an R-rated spin-off "Star Wars", but Lucasfilm wasn't interested in his ideas. It was eventually retooled into a stand-alone work.