Was originally set for a release in the summer of 1997, but held back because of the negative reception following the release of Batman & Robin (1997), which also featured Mr. Freeze as an antagonist. Nevertheless, upon release, the film received strongly positive reviews compared to Batman & Robin.
Batman creator Bob Kane died eight months after the film's release, making this film the last adaptation of the character that Kane would live to see.
A sequel entitled "Batman: Arkham" (not to be confused with the video game series of the same name) was greenlit by Warner Bros. Boyd Kirkland would return to write and direct, and the cast of Batman: The Animated Series (1992) would reprise their roles from the TV series, along with Angie Harmon as a new character. Steven E. Gordon also drew some concept art and character designs. The plot involved Batman and Robin fighting some Arkham Asylum escapees. The project was canceled in favor of Batman Beyond: Return of the Joker (2000).
In the scene with Barbara Gordon's roommate in college, the background music is "Am I Blue", which has another connection to Batman. It also is featured in the animated This Little Piggy (2004), in which Batman sings this song on stage in order to save a friend. Batman & Mr. Freeze: SubZero (1998) and Justice League are part of the same larger universe and continuity.
The second film set in the DC Animated Universe.