Lack of clarity:
1. Unless you are very conversant in Mandarin or Cantonese then subtitles are necessary. But, in this case they used a barely visible small English font; poorly chosen font type for readability; most egregious was using white when most often the background was a light color or white itself. Thus a lot of important dialogue or viewing scenes were lost in trying figure out the dialogue.
2. Unless you know that period's history the script jumped around without clarity of location, characters, or cultural behavior.