The final episode is a meta look back, with Bat-Mite (voiced by Paul Rubens) trying to get "The Brave and the Bold" cancelled in favor of a darker Batman series. It's actually quite clever and the final gathering in the Bat Cave of all of the show's guest stars (including B'Wanna Beast, somehow alive again after dying in "The Seige of Starro") was a lovely send off.
This series broke the moldon what a Batman show had to be. It didn't have to be dark or dramatic. It could be lighter and funny and still be Batman. There is a new Batman show coming up, but I doubt any upcoming super hero series reaches the goofy but glorious heights of this show.