I will consider it as an avg drama.

Talking abt plot, well the concept of birthstone and sleeplessness of princess is really interesting and has been used pretty well. I think it could have been better if they didnt dragged the drama by adding the jealous anagonist part(which happens in almost every love story and is most annoying part)and rathar actually finding a solution to the birthstone sickness that princess had. moreover it rathar ended pretty tragedically. whereas in additional special ep she woke up out of no where. Other than a good concept, it was a really typical love story with one the bold hero,the naive heroine , the scheming villane and certain side chars and nothing much special.

Acting as always, i really adore cdramas for they get the viewers connected to the story nd it was pretty good in this one too. music was pretty cute and well settled in the bcakground

Overall its an avg drama of a typical lovestory with a good concept ehich is not used efficiently, and a dragging story by stupid making love triangles. I myself will really not prefer to rewatch this drama