He also wanted it to be more in the style of his previous realist films. The Ipcress File therefore became the first of the nominally rival Harry Palmer series and some aspects are reminiscent of film noir.
The director's goal was to make it more comparable to his earlier realistic films, which ultimately led to The Ipcress File being the first part of the Harry Palmer series that was often seen as a rival to other spy film franchises. Some aspects of the movie share similarities with film noir.