There were a lot of unofficial MLP RPG games before River Horse got this fully licensed and official RPG out of their stable. River Horse specialise in licensed product, and this is really true to the feel of the TV show while allowing you to generate your own ponies to play through the... well, they've published quite a lot of scenarios.
River Horse say this about what a RPG is, in case parents are slightly confused. And its kind of sweet, so i want to share it here:
A Roleplaying game is something that almost all children do very naturally, playing house or pretending to be your favourite character in a TV show is a roleplaying game at its very core. Role-playing is a very important part of growing up, learning empathy and using teamwork; Tails of Equestria, in particular, is about friendship and all of its elements, exploring new ideas and concepts in a safe environment where anything is possible. The wonderful thing about a role-playing game is that the story can be tailored and changed by the GM depending on the group they are playing with and the lessons that they may want to teach. For example, an adventure in which Fire Brand discovers a band of greedy diamond dogs who refuse to share may well teach the player a little something about why sharing is important!
Seriously, you don't have to be into MLP to love this game. Well, OK, really maybe you do. But even if you aren't a Brony or a Pegasister (or you have kids who are) the central theme is great, the game system itself is sound and the adventures are a hoot (like the show itself, they don't take themselves too seriously).