I was hesitant to watch this show due to following reasons : -

1. Age gap between the character (not the leads)
2. Go-eun as Tae-eul in TKEL
3. Being a melodromatic fantasy
4. Not available in NETFLIX


+/- Story &CAST
- The actors do a superb job. I could feel their emotions from across the screen. then again, nothing less to be expected from such a spectacular cast.
-The drama has everything, ranging from bromance, romance to mystery and suspense.
-The bromance is spectacular. One of the most epic bromance I've ever seen in a Kdrama. It made me laugh a lot, but it also had its heartwarming and heart-wrenching moments. Goblin and Grim Reaper's relationship is one of the best reasons to pick this up.
-The two couples- Goblin & Eun Tak and Grim Reaper & Sunny. Both couples had their own story. The sweet and cute moments of the Goblin couple & the sizzling chemistry between Grim Reaper and Sunny was enough to keep the 'romance' meter of the drama pretty high. You won't be able to get enough of the cuteness of Goblin & Eun Tak.
-The mystery of the characters. From 'the lady in red' to the king and queen, each episode just gave enough glimpse into their lives to keep us engrossed. It'll drive you crazy in a good way.
- Gong Yoo was amazing and Go-eun was very good well suited for this show. I almost didn't watch this show because of her role in TKEM which was badly written.


+/- Music:
All of the music was perfectly interwoven with the filmography! I couldn't believe my eyes and ears when Gong Yoo and Lee Dong Wook came strutting down the dark road, it was just pure matrimony. I am a huge fan of the soundtrack and have been listening to it on repeat for at least 2-3 days straight. My favorite song from the album changes from day to day, so that tells you that all of it is simply amazing.
BONUS: Beautiful and addictive OST

+/- CONS:
I personally didn't find anything even remotely bad about it, but that's not to say other people won't, so here's a few things you should keep in mind before venturing into it.
-The age difference between Goblin [ (~939) he was 39 when he died and then immortal for 900 years] and Eun Tak (19). Although the age difference between cast is 10 years so i didn't feel weird in most scenes . [spoiler] Their first kiss was after they she turns 20 and they don't skin-ship in school uniform Compared to Doctors show where they have similar age difference[/spoiler]
-Comparatively less screen time for Sunny and Grim Reaper couple. But I suppose that's to be expected specially since the title alone indicates that Kim Shin (Goblin) is the main lead, so it's no wonder they get the most screen time.
-Worst product placement you'll ever see in a Kdrama. You might think I'm kidding but sometimes even the smallest thing can annoy you. I personally found those scenes amusing though.

Overall its a good drama and although at times the plot is slow you will still enjoy the ending... Although i rate this highly it still doesn't have a rewatch value as their is around 40-50% of plot thats very slow paces and almost like a filler.