This series contains the largest cast of DC comics characters to ever be seen on television, film, and video games as of 2012, featuring the most famous, iconic characters to some of the more obscure ones (eg. Egghead, King Tut).
As of 2012, this is the only Batman TV series that has Batman directly confront Joe Chill, the man who killed his parents, and initiated his one-man quest for vengeance and crime fighting. Previously, "Batman Begins" dealt with Joe Chill's consequences, but did not feature a face to face battle between him and Batman.
In the Season 2 episode "Chill of the Night", which was agreed upon by fans to be one of the top 5 best episodes of the series, is also distinguished by having a few Batman-veterans making voice-over cameos. From "Batman: The Animated Series" (and its spin-offs), Kevin Conroy (Batman) voices the Phantom Stranger, Mark Hamill (the Joker) voices The Spectre and Richard Moll (Two Face) reprises his role (very briefly) as Two Face and as the mob boss who hires Joe Chill to kill Thomas Wayne. Also, from the "Batman" (1966) series, Adam West (Batman) and Julie Newmar (Catwoman), voice Thomas and Martha Wayne.
The series adopts the look and feel of the more innocent comic books of the 40s, 50s, and 60s, but makes use of characters and characterizations from the general history of comics. The tone is mostly comedic and adventurous, but can have many moments of generally heartfelt drama. The series is not, strictly speaking, a kid's series but a family series, intended for viewers of all ages who enjoy superhero culture.
In the second season episode "Requiem for a Scarlet Speedster," The sound effects used for the various Flashs' running is that from the 2001 "Justice League" series. The only (hilarious) exception to this is during the final confrontation between The Flash and Reverse Flash. When they are running through the desert, the sound effect is that from the "Road Runner" cartoons. Both the Looney Tunes and DC Comics franchises are owned by Warner Bros.
The series is very notable for mixing multiple storytelling and cinema genres, styles, motifs and wide-ranging cast of characters. It was not uncommon for Batman or someone else, to end up in the fabled city of Atlantis in one episode, then turn up in an alternate dimension in another, only to end up teaming up with Sherlock Holmes and Dr John Watson in another.
Although Batman's regular look in this series is that of the Dick Sprang era of the 50s, many of his other incarnations appear at least once throughout the show's entire run. These include his vampiric version from the "Crimson Mist" graphic novel, his hardboiled version from Frank Miller's "The Dark Knight Returns" and even George Clooney's portrayal from "Batman & Robin" (1997).
James Tucker, one of the creators of the series, was most notable for working on "Superman: the animated series", "Batman Beyond" and "The New Batman Adventures". The series itself pays homage to those series, even on a visual level.
Based on the DC comic book of the same name that debuted in 1955. Each issue of the comic book featured two characters or groups teaming up to fight a stronger villain; unlike the TV series, Batman did not become a permanent fixture of the publication until 1960, and then only until 1983. The initial run of the publication was from 1955 to 1983, but was revived (without Batman as a regular character) from 1991 to 1999, and again from 2007 to the present.
The trivia item below may give away important plot points.
In the episode "The Legends of the Bat-Mite", during the 5th demensional comic con, one of the cosplayers in the front row is seen wearing a Christian Bale Batman/ The Dark Knight Trilogy Suit. As well as another person in a red hood outfit.