"Heart of Darkness is a 1993 television adaptation of Joseph Conrad’s famous novel, written by Benedict Fitzgerald, and directed by Nicolas Roeg. It stars Tim Roth, John Malkovich, Isaach De Bankolé and James Fox. It is the third screen adaptation of the novel, following a 1958 television adaptation for the series Playhouse 90, and 1979's Apocalypse Now, which loosely adapted it and updated it to the Vietnam War." via Wikipedia
You should be able to tell why this was only released on VHS and LaserDisc. Definitely not as brilliant as Roeg's other films.