I was intrigued by this drama because the MVs were so intriguing, but after watching the first 2 episodes, I just wasn't feeling the story enough. I decided to look up some spoilers about how the story turns out in the end to decide if I wanted to dedicate all the time in watching the drama all the way through based on how the ending turns out. I'm so glad I looked into the spoilers because I am most DEFINITELY not happy with the ending (regardless of whether certain characters deserved their ending or not).
The story was dark from the beginning and I am not one to watch dramas if they are dark, so for me, it would never work unless the plot is simply AMAZING (like the drama, Tunnel - I just couldn't put it down, no matter how dark and horrific the events were). Anyways, for me personally, the drama was not intriguing nor enjoyable enough for me to keep watching, and then with the way the ending turns out, I just couldn't justify continuing to watch it. In my opinion, this is not a drama meant for everybody.