Continuity mistake: There is a color change on Darkman's burned skin. In the beginning of the movie, in his lab, his burns are pretty much flesh colored. Later on in the movie, they are a much darker red and brown.
Continuity mistake: In the opening credits, we see a re-cap of the first film. If you pay attention, in most shots Peyton/Darkman's eyes are a dark color. However, in one extreme closeup, we see one of his eyes and it's suddenly bright blue. (From where footage from the first film, featuring a different actor with different colored eyes, was used).