When I first heard about this drama and the influx of supporting idol actors, I was very skeptical.
The beginning was extremely painful and it only got interesting around episode 4/5.
I think the storyline could have discussed Eunjo and Annie's circumstances for longer, especially focusing on the mystery of Eunjo's disappearance.
Maha and Ryok's romance was lackluster, they had chemistry but the writer's skills were lacking a bit. I was far more interested in the friendships of the different idol groups than the romantic relationships. Certain things were not making sense, but it seemed that the writers' purpose was tie everything into a pretty bow which ending up leaving a lot of plot holes.
The music production was terrible for almost all the groups except for Tea Party which was disappointing but I'm assuming that budget was smaller than they had anticipated.
Overall, it was better than I thought, but the ending was lackluster and I probably would've rather binged the show that spending 12 weeks watching each episode.