I think it's a good adaptation. For people who want to watch them, I think I should mention that if you looking for adaptation that 100% accurate from the webtoon then this isn't the for you because there indeed some change in the story.
The drama is more focus on the other character especially the one with short screen time in the webtoon, like the 2 children and the other survivor. There also new character and I think the chemistry especially the romance one is improve in the drama.
The CG is not that great but it capture the scary as good as the webtoon. The cinematography is also great but be prepared with the "Imagine Dragon-Warrior." Ost lol.
Anyway I think it's a 5/5 from me.