When I started watching the series, I was very excited as the topic was unique though it had mistakes (they never tried to find why the spheres are up in the sky and what are those exactly, they just continued their normal life even though those abnormal spheres were in the sky and when one of them fell, it never showed what exactly happened) . Whatever, upto part 1 it was good. In the 2nd part, I am curious where Kim Won Bin was like is he some imaginary character that disappeared out of nowhere? And even when it was a month they were fighting by themselves, there was no change in their whinings like they never matured. Situation changes people but ig they are out of this range. And the ending, it was worst like they just needed to end it. Worst ending ever. They could have described things more clearly even if it increased the no of episodes it would have been of worth. I will never watch another drama without reviews . Those who are planning to watch this, I would suggest DON'T, JUST DON'T WASTE YOUR PRECIOUS TIME!