I was so disappointed by this. I really love period dramas (sageuk), but perhaps I had the wrong expectation. I really shouldn't expect too much of 12 episodes. I really wanted to love it - I love both the leads. The plot elements could have been fantastic together: there was a underhanded scheme going on with a mystery. There was a super clever maid. There was a sad king. There was cutesy chemistry between the two leads. There was a second lead romance. There was a brave sidekick. There were hilarious sidekicks. The first few episodes were funny.

Don't get me wrong, I can and do appreciate well crafted sageuk not based on history e.g. Red Sleeve Cuff, Rooftop Prince, and most recently, Bloody Heart.

However, this was an idol drama; nothing more, nothing less. This was a fantastical (ie I'm being sacarstic and rolling my eyes) drama.

The story suddenly introduces new characters and new plot points in the final few episodes.

SPOILERS
She survives attempts to kill her, jail her, etc etc so easily.
She SUDDENLY became eligible to be queen due to her newfound eligible heritage. (not previously mentioned)
The sidekick who was poisoned and his hand whitered away yet SUDDENLY and MIRACULOUSLY he survived and his hand heals.
She was SUDDENLY saved by someone who would become a key ally, in the last 4 episodes. We hadn't seen this person previously.
END SPOILER

I'm going to attribute this to the fact that there were only 12 episodes. No self-respecting sageuk can unfold over just 12 episodes. The writers didn't weave in a backstory (probably not enough episodes to). They simply threw assumed facts in your face to solve key plot points.

My only plus point: precisely because it was only 12 episodes, my pain wasn't prolonged.

In short, have the correct expectations when starting to watch this. Watch it because it's entertaining if viewed from a modern lens, like a fantasy drama. Do not expect an intelligent, authentic, sageuk experience.