Perfect action type of drama. There are sad scenes, annoying villains, a little bit of comedy and a little bit of romance (personally I wished there was a little more). Lee Seung Gi and Bae Suzy's chemistry was on point. The only thing which is almost always point out is the ending. For many people open ending was the worst decision, personally it does not bother me. Also many people want second season, if there will be I will be happy, do not get me wrong, being satisfied with ending does no mean I do not want to watch more about charcters, although I am not sure if we will ever get next season.