Taking into consideration that this was filmed in 1920, Dr. Jekyll and Mr. Hyde is astonishing to watch. In terms of character development, scene composition and editing, this set a high benchmark for other films to follow. Although it is not the first horror film to be created, it most definitely paved the way for others to follow in its footsteps.
The film is an adaptation of a story by Robert Louis Stevenson as well as the play written by Thomas Russell Sullivan. John S. Robertson's direction is marvelous as he is able to convey a great deal of emotion and storytelling without anyone saying a word. He really captures some great performances from his actors, most notably John Barrymore [grandfather of Drew Barrymore] in the dual roles of Jekyll and Hyde. The scene of his first transformation is tame by modern CGI standards but shocked the you know what out of his audience in 1920. Without any cut-aways, Barrymore's face actually appears to begin transforming simply by the manipulation of his facial muscles, the angle of the camera on his face, the movement of his hair and the change in his body posture. Bravo! Eventually the prosthetics and full makeup come along but the transformation is wonderfully noticeable before any of this is applied.
Dr Jekyll and Mr Hyde explores the theme of the dark side of human nature in a way that would inspire numerous horror films to follow such as The Invisible Man (1933) and Mystery of the Wax Museum (1933). If you have any interest in films of the Silent Era, this one is not to be missed. The full movie can be seen on YouTube or is included in many inexpensive vintage horror anthologies.
For more info check out the film's entry in IMDB.