It’s easy to understand why this film launched Steve McQueen’s career; he truly maximizes his limited screen time. While the jungle sequences are passable, cutting the romantic subplot between Frankie and Gina wouldn’t have hurt anything—there was simply no spark between them. In fact, the Burmese girl seemed more compatible with him, aside from her involvement in espionage. Peter Lawford, however, felt like a letdown; he appeared to be going through the motions. The rest of the movie is adequate. Seeing McQueen's initial leading role made the two-hour runtime worthwhile, but I wouldn’t choose to watch it again.

Source on TMDB