How others will see it. A competent adaptation of the Rudyard Kipling classic, most who see the film couldn't care less about the real question that the film raises. Namely, what were the British doing in India in 1885? Less polemic than, for example, Gunga Din (1939), the villains of the film are not the rebels, but their suppliers: troublemaking agents of the Russian Czar.
Most who see the film will instead concentrate on its hero, Kim, and his clever, willful, and often dangerous adventures. Errol Flynn technically gets first billing, but in fact has only a middling supporting role, and even his romances are little developed.
Will Kim hold the interest of its audience? Children, probably not. Adults, yes, if they appreciate classic films, and enjoy stories about British controlled India. But the workmanlike film burdens young Stockwell with the task of carrying the movie, and although he has satisfactory pluck, the magic isn't there, and the film is unmemorable.
How I felt about it. I am not familiar with Kipling's novel. I did read some of his other works when I was much younger. He's pro-British, of course, but respectful of India's rich (and from a Western perspective) exotic culture.
I suspect that Hollywood has condensed the story to the point that the plot depends upon dubious coincidences. For example, Kim is reunited with Mahbub Ali on the evening that plots against the latter's life must be thwarted. Later, Mahbub Ali locates Kim with the Russians, on the day that Kim requires rescue.
Such timing finds drama, of course, but it comes out contrived. Wouldn't it be better if Kim and Mahbub Ali straightened out their own messes? The character of Mahbub Ali also seems crafted to provide a role for Flynn's flagging career. A 'man of peace' who exults when a series of boulders crush an advancing regiment of tribesmen. A 'horse trader' who must travel across the country to sell the few horses that accompany him. Not a convincing front, and his affairs with sultan's mistresses don't help his cover.
For a great story about a British tyke in Victorian-era India, I suggest Wee Willie Winkie (1938) instead.