The idea of a remake of the classic from the 40s starring Bacall and Bogart, with Mitchum in the role of the detective and directed by the same guy who helmed Death Wish, The Mechanic, and The Sentinel, should have resulted in a more exciting, even brooding adaptation. Furthermore, with the removal of any Hays or whatever code, the film was allowed to explore themes found in the novel, such as homosexuality and nudity, that would have been taboo forty years before.
Unfortunately, the final product is significantly inferior. Mitchum sounds more energetic than in Farewell, My Lovely, but all the wit and humor of that film, Bogart’s version, and the book itself have been completely removed. I would argue that these are some of the most essential, if not defining, characteristics of the detective. Sarah Miles is not Lauren Bacall nor Charlotte Rampling (I have just seen those two and this one). Her chemistry with Mitchum is nonexistent. She lacks sex appeal or allure. Though her personality, as eccentric as her hair, makes her stand out from the crowd. In fact, the rest of the cast doesn’t stand out at all, which says a lot when you have heavyweights like Oliver Reed, Joan Collins, and James Stewart.

Back to Michael Winner, the direction fits very well with the almost dreamlike style of that time, especially within British cinema. Personally, I don’t think it aligns well with the style of Philip Marlowe or Chandler. That isn’t the case in this particular film. I think The Long Goodbye goes for that same vibe and works better. This one lacks the key elements that made The Long Goodbye successful, such as a strong script and direction. Jerry Fielding’s music is fine, nothing special. It’s not as strident and melodramatic as Steiner’s in the original. It’s somewhat more atmospheric and “modern,” though I feel that one lacks any true personality.
All in all, it isn’t a complete disaster and the plot of the novel it’s based on is good enough not to ruin, so it’s not entirely boring. But yes, I think they took the movie’s title too seriously; it lacks any of the excitement and all the things that make the best Marlowe adaptations great.