I prefer to go into show blind as I find it better to reach my own conclusion and/or opinion on a show.
I normally like detective style shows but this is one of those ones that I dropped simply because I didn't like the characters.

This show uses some pretty heavy material for it's mysteries which if you are anything like me, will put the anxiety through the roof as your watching. This show was not good for my heart in that aspect. So if you are sensitive to very violent source material, be warned here. When I meet material as dark as this, I need to have something to counteract that kind of information. I need deeply heroic people and compassionate people. I am fully aware this stuff happens in life and the people responsible get to walk. I do not find it entertaining to watch it in a show. I am a viewer who doesn't need step by step reality in my shows.

Having said that, the characters fail me in this. The leads are the only truly likeable people, at the start. Everyone else is a truly an evil person. There are no excuses here. It's a kill or be killed kind of reality. I get it. The past sucked.

Our 3 main leads are a stoic and solemn guy with a violent past, the effeminate baby girl genius guy with a sad past and the hard nosed palace eunuch that you're not sure whether or not to trust, and I couldn't be bothered to find out his past.
I can understand this set up in the beginning but they were still the same by episode 20. I knew nothing more about them other than Stoic guy is kind, everyone hates the eunuch and the effeminate ML is as annoying as all hell.
I don't do tsunderes. I don't find them cute or endearing or even funny. They just annoy me. 20 episodes in and our ML is supposed to be exceptionally intelligent. He is the 'sleuth' in the main title and yet he will pout and stomp is his feet like a baby, rush into a situation on emotion and will straight up tell the Emperor to go away because no one is above the law and I just don't want to. I'm sick, I'm getting married, I'm dead. Seriously? This is our Genuis ML? The Emperor could have you and your friends gutted on the spot. Is a bit of tact too much to ask for from our supposedly competent genius? Am I supposed to cheer this on?
The surrounding characters aren't very fleshed out by episode 20 either. We've got the super genius adopted sister who remains in the background eating sweets until she's useful and two foreign characters that are just kind of there. They fell into the plot randomly and now there's a romance trying to be pushed between foreign girl and the ML.

Also, the food p@rn. I really don't care for. Am I supposed to feel something? Was this to counteract the absolute devastation of the mysteries? It does nothing for me.

First time in my life, I also found the cinematography annoying as well but perhaps that's just the mood I had when watching. Someone really loved getting picture-esque shots between doors and at side angles with lots of props in view. After a while, this started to give me a slight headache as I tilt my head with the camera. Yes, the surroundings are beautiful but every other angle doesnt need to be up and down and side to side.

Overall, I can see the appeal if detective shows are your thing. Not alot of action. It's all sleuth or at least until 20 but it is an exhausting show to watch. From the annoying lead, the camera angles, the dark material and deep web of lies and deceit in the royal court, there was just too much going on for me to be able to enjoy it properly.