This has been on my 'to watch' list for sometime, i tried several times and finally got past the first few episodes and I was HOOKED. It is a rather slow burn story development wise and does become a bit....too much in some aspects but it is well worth the watch.

One downfall for me starting out was the length of episodes, this could have been split into more episodes or even a possible second season with how confusing and somewhat unbelieveable the story seems to get, with its many developments and twists. Though it did seem somewhat confusing at times it was easy enough to follow once the "twist" had been explained but characters.

The acting is good, honestly the main baddie "S" I'll call them, amazingly acted and honestly was such a great choice actor wise I'd rewatch for their scenes alone.
I'm really a sucker for anything with Park Shin Hye in it was she was amazing as usual.

I feel they could have expanded the OST just a little, the same few songs were a bit much during the ending credits but the overall music in the show was pretty typical.

In all honesty, give the show a chance, it may seem a bit much and might not be your cup of tea but it is such an interesting show for the k-drama genre that i'd really suggest.