I loved the first two seasons and so did my nieces (5 and 8) The art style was cute and bright, the music was really catchy to a point I'd find myself humming along while cleaning house, and the overall plot was surprisingly good! I went in expecting something for a five year old with little plot and characters with no personality and actually found myself watching it even without my nieces when I discovered it had both. I'm glad I gave this a shot and it's not annoying like some shows my nieces watch over and over and... though you do need to keep in mind it's for kids and if you can't stand shows like My Little Pony or Equestria Girls you most likely will not enjoy the silliness or voices in it.
Anyone who enjoyed My Little Pony will enjoy the familiar voice casting of two of it's main characters (two of my favourites actually) and I urge people to find the show and really give it a chance. It's better than you'd think and not nearly as annoying as some other shows out there! My nieces like to dance to the music and want to dress up with the little concerts at the end of each episode. Would be cool for a little doll and costume line to come out in the future. (Hey Mattel, get on it.) I know I'll have to buy the girls little toy microphones this Christmas now at the very least.
I did see a couple complaints online of a character using the word hell ("Hell yeah!", specifically) once out of two entire seasons (Okay Karens hakuna your tatas. Your delicate flower has and will hear far worse at home from your own mouth.) and honestly I completely missed that myself if not for reading the comments on a random reddit post on a search to find out why it disappeared off Netflix. I know my nieces totally missed it because they love to copy anything they hear.
I genuinely found nothing to fault the show except that (and, again, keeping in mind it's created for kids) the villains are made rather painfully dumb albeit charming little oddballs. (Think Jesse and James in Pokemon.) And the animation is a little... twitchy (for lack of a better word) at times but the visual details put into every scene completely make up for it.
Overall, great show! My nieces loved it. I loved it (and I'm not a fan of musicals or shows based around music). We're looking forward to a Season 3 and I'm hoping for a toy line for my nieces similar to Monster High and Ever After High (their other favourites after MLP).