If I am to be honest, I should have given 4 instead. The bonus 1 star is for the nice surprise when mainland China movies almost always disappoint me. In mainland China, very few actors know how to act, even fewer directors know how to tell a story (IMO anyway). Not this one. Some part of the plot are less convincing, some scenes are a little over the top, but nothing too bad to ruin overall quality of the movie.
Both main actors are impressive, I am especially impressed by Enyou Yang's performance, incredible for her age. Director Jiangjiang Liu has done a great job, however I feel he could have added some calmer/quieter frames here and there. The movie tries to be emotional/tense from beginning to end, which doesn't give best view experience.