It is an idol anime in the sense that it has dancing and stuff, but the story and flow is more like fantasy.
Feels like the typical mass-produced commercial mobile game / media mix that is adapted into anime. Actually feels decent for the idol genre, but this says more about how bad the idol genre is on average that by moving away from it you get a better overall result.
Nothing remarkable. On the plus side, it didn't make me angry for watching it. I guess if you want something different and you have already watched the better stuff out there... and even then... there are better options for your time.