Two actors who previously played Batman have made appearances on the show: Adam West and Kevin Conroy. Adam West played Mayor Grange and Kevin Conroy played John Grayson.
In terms of overall tone and style, the series is based principally on the original stories from the early Batman comics from the Golden Age until the late 1960's.
Scarecrow, Ra's al Ghul, and Two-Face were restricted from appearing on this series, because of their planned use in Christopher Nolan's live-action The Dark Knight movie trilogy. Scarecrow and Ra's al Ghul appeared in Batman Begins (2005) and The Dark Knight Rises (2012), and Two-Face appeared in The Dark Knight (2008) (which also prominently features The Joker, but since he is Batman's greatest enemy, he was allowed to appear on the series). Bane and Catwoman were never restricted, because development for The Dark Knight Rises (2012) did not take place until this series ended.
The Edge (Dave Evans) from U2 performed the opening theme. Season three featured a new opening theme that was a cross between the Neal Hefti themes from Batman (1966) and Hawaii Five-O (1968). Back in 1995, he and his fellow U2 band mates played a song for the Batman Forever soundtrack called "Hold Me, Thrill Me, Kiss Me, Kill Me".
This was the first Batman animated series to feature Professor Hugo Strange in multiple episodes. The character has never appeared in more than one episode in any previous Batman, or DC animated series. Strange is one of Batman's first recurring villains, preceding The Joker and Catwoman in the comics by several months.