I'll start this by making clear that i have not read the original webtoon so I'm writing with just the drama in consideration.

First of all this is definitely not for everyone. a lot of death, violence, gore and mentions of triggering things that even i, as someone who doesn't really get affected by these knowing it's fiction, had to take small breaks or look away. i guess what you'd expect from a horror, action focused drama.

Even so, this drama was so interesting and attention-grabbing i couldn't stop watching. The story is incredible and somehow, especially now with the pandemic and everything, felt real. Every single major (if not almost every) character is well written with intriguing back stories that reflect on their motives and behaviour and very easy to sympathize and get attached to. The way they interact with eachother feels realistic and the relationships built between them are natural. There's also big diversity in characters for everyone, even the characters that are written to be disliked in a way can be understood. The actors did an amazing job delivering the emotions of the characters and bringing every scene to life, which is exactly why you most likely won't survive watching this without balling your eyes out.

Suprisingly, unlike most kdramas, the comedic breaks are minimum which keeps you on your toes throughout the whole show and even when there are such breaks it doesn't fell like filler but rather an easier way to get to know the characters and their dynamics better.
The special effects and cgi were decent and looked mostly realistic and the camera work and setting gave a chilling and classic korean horror vibe. The ending also lives a big opening for a season 2 which I'm really hoping for.

All in all, this is a beautiful and heart tugging story of seeing tragic but powerful characters trying to survive and go through hardship after hardship yet still continue to fight, stay hopeful and not give up. Definitely a good watch.