Sylvester Stallone was originally in negotiations to play the antagonist Firefly, but an agreement couldn't be made. The role was then offered to Brendan Fraser, who immediately accepted.
Following the film's cancellation, Adil El Arbi and Bilall Fallah attempted to capture some of the footage for private use. However, when they accessed Warner Bros. Discovery's server, the footage could not be found. It is assumed that it was deleted in order to prevent the film from leaking.
Secret "funeral screenings" were held on the Warner Bros. lot to cast, crew, and executives before the film was locked away.
Batman (1966) producer William Dozier requested that a female heroine be created for the Batman comics so he could use her on the show. The character Barbara Gordon, daughter of Gotham City Police Commissioner James Gordon, debuted in Detective Comics issue #359 (cover-dated January 1967) written by Gardner Fox, drawn by Carmine Infantino, and edited by Julius Schwartz. After DC Comics confirmed to Dozier that Batgirl was a permanent addition to the comics, Dozier added the character to the show. Her television debut was in the first episode of the third season, Enter Batgirl, Exit Penguin (1967), played by actress Yvonne Craig.
The film was set to be the first DC Extended Universe movie to premiere exclusively on HBO Max. At one point, there were plans to give the movie a theatrical release first. However, following the acquisition of Warner Bros. by Discovery, the film's release was canceled in August 2022 when Warner Bros. Discovery deemed it unsuitable for release.