Lee Joon is phenomenal in this drama. Also the storyline is probable and interesting, although the end is predictable to some extent. Great production. Believable story, with lots of suspense and guessing of who on the crew is a bad person. Visuals are really well done too; the moon scape. In some spots there was too much time spent on characters roaming around. It was done to create suspense, but felt more like a time filler. There was good character development for some of them and backstory was just enough without getting annoying. It's not a 10/10 for me, because there were some VERY cheesy gore/thriller moments that could've been done better. Also I wish we knew a little more about some of the characters, like the one played by Lee Joon. However it's a great watch and I binged it!