The character of Mayakofsky (Joe Pesci) is a thinly disguised name for real-life mob boss Meyer Lansky. According to Wikipedia, source novelist Marshall Houts "proposed the theory that American gangster boss Meyer Lansky was behind the killing of (Harry) Oakes (the real-life person on whom Gene Hackman's Jack McCann was based), due to Oakes' resistance to casino gambling in the Bahamas."
Gene Hackman once said of this movie: "It's not an adventure story, although it has all of the elements. It's not a straight mystery, although it has a lot of mystery involved in it. It's not a drama of a family, and yet it has that too. It also has a variety of locations - everything it takes to make a really interesting movie."
Director Nicolas Roeg has said of this movie: "I was initially interested in a character who wanted to satisfy an all-consuming desire...'that's what I want'...but when he gets it what happens after his brief ecstatic moment? Nothing more than left over life to kill."
Leonard Maltin has commented that this movie was "shelved by its studio, (then) sporadically released in (the U.S. in) 1985". According to Senses of Cinema, this movie was "produced under the aegis of David Begelman's troubled reign at MGM/UA, Eureka (1983) was shelved for almost two years and then dumped into a handful of cities."
When Jack finds the gold, the music is from the beginning of Wagner's Das Rheingold.