From 1975 to 1978 DC Comics published a title called Batman Family which focused on the Dark Knight’s supporting characters. They were mostly Batgirl and/or Robin stories that had little or no interaction with Batman himself. This original DC Universe movie made me think of that series. While Batman Family would not be as “cool” a title as Batman: Bad Blood, it would be a lot more fitting.
After the break I’ll look at the movie in a bit more detail and try to be as spoiler free as possible.