I loved the high quality of this drama, it is extremely well made.
The story is certainly intriguing in that it keeps you wondering how all the conundrums could ever be rectified; the story portrays a veritable railing agains the Gods if you will. The characters are in a perpetual dance of push and pull with fate and destiny, while watching I always got the mental image of puppets dangling on strings pulled by a kind of sadistic puppet master; what makes the drama interesting is the gradual growth and self awareness of the characters which allows each one to make some decisions which do not appear to be orchestrated by the 'puppet master'.
There is a strong sense of doing good deeds and being kind, especially with regard to goblin, and also with goblin's bride when she makes the ultimate sacrifice. I got the sense that this 'goodness' eventually positively impacted their destiny.

I love the casting, especially with regard to the goblin, the grim reaper and Sunny. Whenever these three were on screen, together or individually, it was absolute magic!
I'm sure I don't need to expound on the genius that is Gong Yoo, he has an uncanny ability to portray his characters so sympathetically, realistically and humanly; he imbued goblin with such pathos, simultaneously making goblin vulnerable, eternally sad yet strong and hopeful all at the same time, he is truly gifted as an actor.

The grim reaper is an absolute revelation, Lee Dong Wook took this character to levels that I feel only he could take it, he seemed made for this role. His sadness is less hopeful than goblin's, he is always resigned to his unhappy fate, while being oblivious at the same time because of his lack of memories. He is the character that shows the most emotional growth in the drama.

Sunny has the appearance of someone without much depth, and yet she turns out to be very perceptive and emotionally intelligent. She seems to already have some knowledge deep down in her psyche even though she's not aware of it in the beginning. she is complex and many layered.

Eun Tak portrays her youth in a cute, bubbly manner and she is a ray of light for the other characters. she does portray some maturity at the end of the drama but I'm never really convinced as I keep seeing the school girl in her.

The story of the goblin and the goblin's bride is a beautiful concept, Gong Yoo plays his role to perfection but in my opinion the writing of the goblin's bride as a young girl really threw me off and I was never able to see the two of them as a convincing romantic pairing. I kept wondering why the goblin's bride couldn't be the same age group as Sunny, writing her as a young girl didn't serve any dramatic purpose and actually took away from the feeling of intense fated love that they were supposed to portray.

Sunny and the grim reaper on the other hand were very well matched, their trajectory was realistic, mature and deeply felt. The fact that their story was so slow in progressing actually added to the depth of their storyline and I found myself wishing they had more screen time.

The goblin and the grim reaper had one of the best bromances I've seen in a long time, their interactions were entertaining, usually goofy and yet still managed to convey their growing strong bond of friendship in a very believable way. I really enjoyed seeing them together, especially when they teamed up to achieve a common goal.
Special mention to Deok Hwa for his perfect comedic timing and refreshing 'irritating little brother vibe'

So overall, I highly recommend this drama, it might seem to drag and go around in circles in some places, but it is definitely well worth the watch.

PS: all the cast have a prodigious amount of beautiful coats!