One can easily understand why this drama is such a hit among fans. It has only six episodes, which are fast-paced but still give enough space to all the characters so we get to gradually know more about them. Each of the students is different, with different goals, dreams, and attitude, but when they come face to face with the alien menace, they are able to put theses differences aside and try to work like a proper team.

This drama is a thriller with some almost horror moments mixed in, one I would never watch when it gets dark and I'm alone, but it was able to surprise me with some gold comedy moments as well, like when some of the students try to desert the school but were caught and were running around while the soldiers were chasing them and a lively music was playing in the background. And there were also moments that were both comedic and heart-warming like when the soldiers prepared the food for them and then the food battle began. Korea really knows how to mix genres well even if just for a few scenes!

The CGI of the aliens (especially the small star-like ones) was absolutely marvelous! I'm looking forward to part 2 of the drama especially if we will get to see the other bigger aliens as well and I can't wait to know what is their origin. And hopefully all the students and Won Bin manage to make it out alive!