Batman Gotham Knights

This marks Rupert Thorne's first appearance in the animated continuity since the original series episode "Bane." For reasons that have never been explained, Thorne was never utilized for the revamped episodes (Gotham Knights). Like Two-Face, Harley Quinn, and Ra's al Ghul, Thorne's appearance remains virtually unchanged from his original design, albeit simplified, but similar nonetheless.

Eli Marienthal takes over the role of Tim Drake/Robin from Mathew Valencia.

The country that the Penguin is selling arms to is Kasnia, which is also the focus of the Justice League episodes, "Maid of Honor."

In her only scene in the movie, Barbara Gordon makes it clear during a phone call with Bruce that she's harbouring some romantic intentions toward him. This is foreshadowing of the relationship that, as Gordon herself tells us in Batman Beyond, they will later develop.

Rupert Thorne is the only villain who maintains his previous voice actor (John Vernon). Carlton Duquense was created for the movie, whereas David Ogden Stiers and Hector Elizondo replace Paul Williams and Henry Silva (respectively) as the Penguin and Bane (again, respectively).

Nightwing is absent in this movie.