Tim Burton was set on making weirder, darker, less kid-friendly characters, while Keaton cut out the majority of his Batman lines to let the suit do the talking.
The Burton/Keaton era was over after Batman Returns and both movies have stood up remarkably well nearly 30 years later.
As it turns out, there was another factor that led Michael Keaton to portray Batman with less words and pronounced movements.
The Hollywood Reporter recently sat down with Burton, Michael Keaton, Michelle Pfeiffer, Danny DeVito, and Christopher Walken to discuss the making of this sequel to the original 1989 classic, which was released on June 19th, 1992.