Yes it's often preachy, yes as others have mentioned it has moments of pure straightforward propaganda. But the story is told with so much real naiveté and the leading actress has so much charm, that it all works. The underlying humanity of it all simply wins you over. You may laugh at certain minutes as some lines reek of propaganda so much it's simply funny, and it still wouldn't hurt the overall effect. I think every viewer belonging to the human race will simply have to root for Yong-Mi on her road to fulfilling her childhood dream and becoming an acrobat. It makes sense that she wins the hearts of anyone trying to stand in her way, simply because she works her magic over the entire crowd too, you know that being in their place you wouldn't be able to resist the enthusiasm and drive of the coal miner who wanted to fly. As I said this has a lot to do with the leading actress, Han Jong-Sim, were she born anywhere else she'd be a global sensation by now or at least a well known star. As it is she's just one more reason to regret the fact that North Korea is practically disconnected from the entire world. A few good words must also be extended to her supporting cast some of these are doing very nice roles too, and to the triplet of directors who succeeded putting the whole thing together, I know I'll be waiting for more at least from the lovely Han Jong-Sim.
