What a wonderful, amazing film! It's black and white and grainy (what did you expect from 1936?), but that doesn't matter at all. No film I ever seen comes even close. It has such a great sense of joy and romantic and adventure, it's so morally uplifting that I can't praise it enough. In addition to that, the movie is so innocent and optimistic that I can't think of a better children's film.
Great actors - I mean, all of them, though I especially liked Paganel, perfect score (by Prokofiev himself, no less!), to the point that "The Uverture for Deti Kapitana Granta" gets ordered quite often on modern FM radio stations - after 70 years! Great songs too ("Oh, Wind of Travel, sing us songs of where you came from", "There once lived a captain brave", etc. Engaging plotline (by Jules Verne), in which daring family of Captain Grant seeks their lost father circumnavigating the globe at 37 deg. South latitude... and so much more!
The only complaint today's viewer may have is dated special effects and not exactly slick stock fotage inserts... But you know what? Who ever notices that when the movie is so great!
I doubt that you can easily find it outside of Russia, but if you even don't find the film itself, do yourself a favour and trace film's soundtrack.