First of all I dropped it the first time I tried watching it. But when I picked it up again and finished watching it recently I was glad I gave it another shot. It was a beautiful drama. As someone who loves beautiful visuals, this drama was a literal eye-candy (except for the horror parts, which were a bit icky). It was also one of the very few dramas which satisfied me in the music part too. The OSTs were amazing. As an audio-visual treat this drama was 10 out of 10. That being said the drama had a good story with some volume to it which was evenly paced and kept me interested to know what happens next. It had it's fair share of loving and touching moments, silly and serious moments, which kept the drama from becoming stale after it hit a certain point (unlike most other dramas which loses their momentum at the half-way point). As a horror drama it's not scary at all, so if you are here for the horror then you will be disappointed.

One of the major reasons I dropped it the first time was the ML. The acting of the male lead felt too stiff and awkward the first few episodes. It was a major disappointment for me at that time and so I dropped it. Now after watching the whole drama I can say, in the later episodes the acting seemed a bit more natural and it was good.
But I was pleasantly surprised with the Ma Go (support) character as the actress did a very amazing job in my opinion. The female lead seemed perfect for her character too. She made the cold character seem very lovable throughout the whole drama.

It's already been a while since it's release, and if you are still wondering whether to watch it or not then don't be like me. Just watch it. It's worth the watch.