We didn't really learn anything about the mane cast of characters in this episode. Some people my take issue with that. I myself was a little disappointed that Fluttershy's stagefright wasn't made into a bigger plot point, or that the mane six didn't really
learn anything about friendship.
But this episode was not meant to be about the characters. Instead, it gives us a backstory for Equestria, and a rather good backstory at that. Once again, we learn how Equestria is a place
Similarly to Secret of My Excess
, I think this episode tries to deal with some of the Fridge Horror
aspects of Equestrian society. Showing the Unicorns as the Aristocracy, Pegasai as the warrior-class, and Earth Ponies as the Peasantry really addresses concerns that I'm sure many fans had. How can there really be harmony between the flying weather-controlling Pegasai, the magically-gifted Unicorns, and the common-folk Earth Ponies? The answer is there can't, so long as ponies put their own selfish interests first.
As a Christmas episode, I'm not quite sure if it works completely. "Peace on Earth, Goodwill Towards Ponies" is a pretty good Chistmasy moral, but the Christmas element seemed a bit tacked on. Hearths Warming Eve feels more like the Equestrian equivalent of the Fourth of July or Bastille Day rather than Christmas.
Speaking of which, the song they sing at the end would work great as the Equestrian national anthem.
I've seen a lot of reactions to this episode, ranging from best-ever to worst-ever. Personally, I really liked this episode. It's not the best of the season, nor is it the worst.
I give it 8 out of 10. There are some flaws, it would've been nice to have some more character moments, but overall it's a very solid episode. The mane six acting out their parts in the play was very entertaining, and the storyline was a nice addition to the world-building mythology.