Feel I need to raise this because Timm has been trying pretty hard to erase the legacies of his collaborators Bon Kane-style, but it was NOT Timm's Gotham. Timm's design work was principally the characters. The world, architecture, and background was the product of Timm's co-creator on BTAS, Eric Radomski. They were co-directors on Mask of the Phantasm for a reason. Similarly, for those who aren't aware, while Paul Dini was obviously BTAS's superstar staff writer, Alan Burnett, ran the writer's room and was the main screenwriter on MOTP.