After having to wait two weeks to watch the final four episodes of the drama, I can say that it wasn't worth it. I dove into Nightmare Teacher with not very high expectations since the description wasn't very interesting or original at all. I was only watching this because of Kim So Hyun and slightly Lee Minhyuk (I have a massive love for all BTOB members). But they only just managed to keep Nightmare Teacher at a watchable level. Small disclaimer before you read the rest, I will have a lot of criticism for this series, but this is all my own personal opinion and I apologize if I offend anyone who enjoyed Nightmare Teacher. The story had a good concept to it, but all the themes and events were poorly executed. Each of the students problems were boring, extremely cliche and it was nothing original. I realize that, in total, the drama had 3 hours of content (12 episodes x 15 minutes) to get through 5 students and Ye Rim's difficulties. But the director should have noticed that more time was needed to be put into each character, so either there should have been more episodes or they could have cut down on the amount of students (e.g. 3 students including Ye Rim, each giving them an hour of character development). I hope that the director learns on this and improves for his next project. The acting in Nightmare Teacher was more tolerable than anything else in the drama. Kim So Hyun was, again, really good like usual, but because of the story's execution, some of her acting choices weren't the best. But I still love her. Lee Minhyuk has the potential to go far in acting, but he still has a long way to go. I hope that as him and fellow BTOB member Yook Sungjae continue in more dramas, he will become a superb actor. Everyone else did decent jobs in acting. Uhm Ki Joon's acting was pretty boring in my opinion, but I guess his role was a teacher, so not disappointed by that. Some of the other students could do with a lot of work, but they definitely contributed to the drama. Music was good, but not at the same time. When the scenes were really tense or filled with suspense, the soundtrack did a good job of creating a better atmosphere. But during any other scene, the soundtrack failed to deliver. But listening back, some of the tracks are noteworthy. I probably wouldn't watch Nightmare Teacher again, it would depend on how bored I would get to want to rewatch this. Overall, Nightmare Teacher has a lot of flaws, but could have done a worse job. The acting definitely saved this series, because if it was based on plot alone, it would fail miserably. But if you're a good fan of Kim So Hyun or Lee Minhyuk, you can give this drama a shot.