Thinking on this, this is the first ever Batman who is actually unnerving and scary. When he’s at a crime scene and the cops are all uneasy around him, and he’s a tall guy dressed really weirdly (and they play on the weirdness of it), it really works. When he fights, it’s not cartoon like over the top like Affleck, but it feels real and violent. He’s actually menacing.
It’s the only iteration where he really has a (non-origin story) character arc. At the start of the film he’s the same as Riddler — Riddler isn’t wrong about that. He’s broken and angry and it’s about vengeance for him. He’s no hero; he’s Travis Bickle from Taxi Driver. By the end of the film he is no longer that person.