I am somewhat surprised that it is even available to purchase -- since it is not the kind of kitschy-bad that can earn a movie cult status, nor notable as any popular achievement either. Its chief virtue is a sort of understated competence.
"Panic..." is plotted as a stereotypical doomsday thriller and the characters are almost, but not quite, cut from cardboard templates. But decent performances and some unusual casting choices for that era give it a certain tragic power.
A romantic subplot between a white middle-aged G-man and Latina doctor is spare, with none of the histrionics you might expect from a low-budget thriller of this sort.
The film's presentation of Los Angeles is a mostly unglamorous town of vacant lots, auto machine shops, shabby apartment complexes, and sterile hospital waiting rooms. The choice of locations adds considerably to its bleak tone. The conspirators operate in this vacant environment, and literally work themselves to death constructing an atomic bomb to use on the city. The nearly-as-anonymous protagonists do not fare much better in their efforts to find and to stop them.
Made in the 60's and in color, but staged more like a 40's "B" picture, "Panic in the City" is not exceptional, but it is not half bad.
