I didn't expect much from this drama, as I have read some negative reviews on it, however, I ended up really liking it.

The acting of the whole cast, especially Han So Hee's, was fantastic and was what drew me into the story more. I read some comments about Park Seo Joon's character and acting being a bit off, but I thought he brought a fun, easygoing vibe that made the show different in a good way. It made me care about his character and his relationships with others and gave a bit of breathing space between all the action-packed sequences.
One thing I wished we had more, was for a slower buildup between the main characters. It felt like PSJ character fell in love too quickly with HSH character. The 'monster' part of the story was good, but I preferred the other conflicts that were in the show. It was intriguing, however, it seemed secondary as compared to other plotlines. Overall, I enjoyed this show and would recommend it!

Side note: Some music in this show felt out of place, but overall the sound, music and VFX generally fit well with the show.