Project GKR is not girly, neither was Star Wars, Enemy Mine, Hacker, and any number of other fantasy sci-fi epics including Team Galaxy, and Brats of the Lost Nebula that this series draws inspiration from.
If all it takes is a female protagonist and colorful backgrounds to make something girly or like MLP then that makes 'The Simpsons' girly.
In fact, there aren't enough guys in cartoons anymore doing normal guy stuff. The closest thing we have going now is American Dad and no one likes fart jokes, and tangental humor that much... except maybe the fox animators, their executives, and their target market.
Although, I must admit, this would make an excellent Nickelodeon cartoon.