I was really looking forward to this as I had watched a few really good dramas with Seo In-guk before, and was wondering about this new show.

Well, this one didn't work for me. The first two episodes had some funny elements although I started to find the side characters annoying because of the massive overacting.
I watched on and for my taste the elements that were meant to be comedy were just way over the top, be it facial expressions, verbal expressions, movements, it all sadly seemed to clowesc for my taste.

I also have to say I don't like the female lead in this role. ( I don't know her from any other shows yet though) She for a change has too few facial expressions and I can't really see her acting qualities in this show. I don't believe for a second that she is a police woman, especially in scenes where she gets hyper emotional, screams like a mad person or beats a man in the hospital bed who has just died and totally loses it, while doctors and colleagues are watching on. Someone with the police can't be that emotional and lose their countenance.

Also I don't buy the lovestory between the leads. It's one of the few shows where I really can't see any chemistry between them: I always felt like I see the actors 'acting while acting'. I'm constantly aware of it. Them just reproducing their lines they learned, I never believe they are really the characters they play or have real conversations.

That sadly goes for the side charcaters too, especially the other couple. Again, way too much overacting, especially the male side character with the way he speaks, when in some situations it's obvious that he can speak normally.
As I think Seo in -Guk was brilliant in other dramas, I can still see why he might have chosen this role now. In the past he was in several rather serious and even tragic roles, - but, and that is the point - in those he was really outstanding. I believed every single second that Kim Moo-young in '100 million stars...' existed, like that person existed for real for example. I still bet doing 'Minamdang' was a lot of fun for all the actors, as it was a funny show and the feeling gets through they might have laughed a lot on set.

I know 'Minamdang' is meant to be comedic but for my taste it it was just too much of these slaptstick elements, so many that I couldn't believe the serious story parts in the background anymore. You can do comedic K-drama and make the characters real and believable to a degree, like in 'suspicious partner' for example. But Cafe Minamdang' just couldn't convince me. At some point I was even fast forwarding and getting impatient for 'something to happen'.
I did enjoy many parts of the soundtrack though.

So, if you are really into slapstick/ hullabaloo shows, this one might be the right thing for you, otherwise, probably not.