AFAIK, "plot" started way back in late 2010 over on that other site as an image macro/meme. Still, without that one line, I'd rate this 10/10 off effort and quality alone, but I'm not a fan of combining even casually-implied lascivious content with the ponies, just wavering on how many points I'd deduct for that.
Putting that one thing aside, I'd declare it excellent and hope for more such projects. They definitely know their way around Adobe Flash.