Hmm... I think the acting is pretty good though? I've watched a lot of Kdramas with plenty of bad acting so I guess it was fine for me. I also don't go into a Kdrama expecting anything because I know that I'll get disappointed at some point
Yeo Jin Goo is pretty good actor (I've seen him act in other dramas before) but his character is pretty hard to portray. It's probably one of the few things I dislike about the drama. I can't quite explain it but I can't connect with the character at all and he seems so one-sided.
You learn more about different ghost's stories in the drama and that's probably my most favourite part. I like it more than the storyline tbh. Those parts remind me of anime for some reason because anime tend to have a lot of side stories alongside the main storyline.
I hope you give it another try ^^