I liked it, specially the first half since there was space for more romance scenes. I did not dislike the second half. I have watched several dramas like this one so I knew there would not be easy solutions to problems and that a spy sometimes has to do things he/she doesn’t want and not be able to do the things he/she wants to do. The ending was more or less what I expected. There was this one character that might not deserve it, but that made me tear up.

Btw, do not expect the female lead to be this super smart and super brave spy or anything or you might be disappointed. She has moments like that but she is mainly a naive girl that does not know time and place, very clumsy and easily gets lost, like literally gets lost, she has no sense of direction. >.<
So try not to go in with any kind of expectations about the female lead’s character. But I can promise you that she will have a lot of character development, so don’t give up on her after watching just 2 or 3 episodes.