Having just finished this drama, I have to say, I'm extremely pleased. I personally loved it, since it was well-executed and always kept me interested. Starting with story, there were two different storylines going on, one being Jae Kyeong's terrifying murders, and the main being, obviously, the story between Min Joon and Song Yi. The story is typical and a cliched plot, but it was extremely well done, and it never had me bored. Around the last bit, it definitely could have been cut, and the last few episodes all kind of mush together, but it was enjoyable nonetheless. There were some things that didn't get tied up around the ending of this though. The original thing that had been so focused on was completely forgotten, that being the fact that it was Min Joon who saved Song Yi twelve years ago, and how she looked exactly like the girl he knew during the Joseon period. That was a completely dropped fact. The other thing that we never really were told was anything about his world. It's really kind of a shame that it ends with such little information on his world, when the entire last part of the drama is focused on him returning to it. The entire cast was great. Kim Soo Hyun made the perfect indifferent alien falling in love, and Jun Ji Hyun made that typical female antagonist character into a main that we all loved. Shin Sung Rok as well, played a chilling but awesome character. It felt like he was oozing evil constantly, plotting the deaths of everyone in his way with a smile on his face. Still, I loved Jae Kyeong as a character; he was so terrifying. The second leads were good too, but they disappear at points of time, and don't get quite enough time for their characters to develop. They were very much used as plot-pushers. The characters were just great though. I felt like, while they were archetypes of every other character we all know in dramas, they were so quirky in their individual ways that it brought a fresh start with character cliches. Do Min Joon was the 'typical cold guy', but even with warming up to Song Yi, his personality doesn't make this drastic change in the name of love, which is what we usually see. The way their relationship progresses and they develop is what I found the best, since it didn't feel like a typical drama to me. I enjoyed the OST, and thought it fit well most of the time, or simply faded into background music. There wasn't any point where it sounded horribly off, and I liked the songs. I am not a rewatcher, but I can see the appeal in watching this over, maybe just for certain scenes. Overall, the ending was a bit weird, but it was great. There was nothing that really frustrated me to the point of anger either, which happens sometimes. The characters and the actors playing them were really the best. This drama is something that ends with satisfaction. I didn't feel like it needed more, and I didn't feel sick like with the usually-cliche happy endings. It was a satisfactory watch, and I would suggest it if you have some sort of interest in great acting and a cute story.