Its not as dark as TAS but I wouldn't say its campy. Compared to many other kids action shows it's still realtively dark. The animation is a little to stylized for my taste though.
Anyway the only gripe Ive got with the show are the villians. The joker is first and foremost a clown, Im not seeing that in the show. He looks more like a drunken master martial artists who happens to have on alot of make-up or something. Mr. freeze becoming just some bank robber who got chemicals spilled on him is just lazy IMO they totally took out what made him interesting as a character. And for some unknown reason just about every villian is a black belt in some sort of fighting style, the penguin making the least amount of sense. But I do look the new origin of clay face.
The show just seems so much more generic now..