The writing can be a little hack, but clearly the animators put a lot of work in. The whole creepy art-deco design of Gotham is really good. Plus there’s lot of cool effects, like Two-Face’s other face being shown in lighting.
I’ve been giving it a re-watch and have been surprised at how good it is.
Bruce Timm and Paul Dini (largely Timm on the art side) really defined a whole generation of cartoon art. Not to mention that most of what people know about Batman and his rogue gallery was invented by them.
The DCAU had some really talent people, be Mark Hamill and Kevin Conroy. Or people like Dwayne Mcduffie and Jonh Semper Jr. during the later years.