Same as you, I loved the main leads chemistry!!! I also liked the message of having to live life to the best of your abilities regardless of the hardships because they are temporary and how important love is whether it is romantic, familial, or platonic <3 

Regarding the conversation of the plot falling, I think it could have been fixed if the writer and made the fantasy aspects clearer/more present in the drama and cut some of the fluff out. Even though I enjoyed watching the characters interactions, at a point it was a little repetitive. Had they had used the fluff time to really dive deeper into something else like Doom's background, DK's illness (the focus was kind of lost after the first few episodes), etc., I think the drama would have received much less criticism.