You could divide this drama into two main parts. One part that is a murder mystery in the style of How to get away with murder, and one part that is taking down a politician that is corrupted to the core, which is more of a typical K-drama. The murder mystery part kind of gets more irrelevant as the show goes on as the second part gets more relevant.
The drama also has other plots that are told, though some that are more important and fits more to the main story (Jeon Ye Seul, Seo Ji Ho) and some that feels more like fillers even though it has some relevance (Yoo Seung Jae, Kang Sol B)
So if you are interested in a murder, mystery drama then this is probably not one for you.

I did find some episodes a bit to slow and almost went down to the boring category but it picked itself up straight away and when the show goes for a satisfying moment, it succeeds really well. Not to mention the last scene of the show is so smooth. Great camerawork and everything.

The acting was fine, it does not have bad acting or anything like that in it, but I did have some trouble with Professor Yang in the first episodes, once again the acting is not bad, but there was something about the character I didn't like but that disappeared after a few episodes. I did like that a lot of the support cast (the students) got a lot of screen time and not just there for filling the spots up so to speak but actually got as much shine as the main cast. And THANK GOD for no romance. I'll admit the scenes between Kang Sol A and Han Joon Hwi was pretty cute and I did like their chemistry but I'm happy it didn't got blown into a full romance cause knowing from other K-dramas I've seen, that plot point would've taken over their (at least the female lead) screen time and not the main plot.

Now the music was simply great. I know I'm not the only one that went nuts every time the 'It's pulling me undeeeer, It's driving me craaaaazy' part came on. The whole soundtrack was great and had a lot of choir/church vibes but still fit really well.

So did I like it? Yes, it wasn't great as in one of the best things I've watched, but I've seen a lot worse. Like I said some plot point where better than others but it is an satisfying watch and worth checking out.