I enjoyed it very much. May people think it is the same old drama but, it really isn't. It was light and ended bittersweetly. At first I would admit it was a bit hard to watch, because it was a bit slow for my taste, but later you get to appreciate all the characters and understand that each and everyone of them has a story and you learn to love all of them. Many people weren't interested in the whole sci-fi and AI concept, but I think they play it very well. Also people were talking about how they didn't contact the police after the incident in the first episode, but Yoo-jin did say that the police just thought it was hackers, and you can see it discussed in the first episode. Personally people should learn to love this drama more and look at it as a whole. I loved the characters, the chemistry, and the cinematography (it was fresh and nice to look at). I want to personally give a shout out to Yoon Hyun-min (the actor who plays both Holo and Ko Nan-do) for making both characters personalities different. You could really tell who was who. If you sit down and you watch the whole thing without looking at individual mistakes, you too can love it as much as I did.