I basically watched this becoz my friends suggested it
And i felt like it was really good. Not the best drama i have seen , but something that would be memorable to me. It has a very deep storyline. I felt like the message which is portrayed is that people can love each other irrespective of who they are.

The journey of Doh Min-Joon and Chun Song-Yi is intriguing and worth watching. Kim Soo-Hyun's portrayal of being an alien was so perfect. He was looking so cute while being enormously handsome. Jun Ji-Hyun also did so good at playing the troublesome actress always being in trouble and having Doh Min-Joon to her rescue. And also i was kind of annoyed by Chun Song Yi's mom but in the end i came to like her.

Now about the OSTs , i am not a big fan of it . Yes , it's good but i didnt like it much. It mostly depends on personal preference

Overall its very good and worth watching in my opinion.