Kind of reminds me of a combination between super monkey ball and those mini-golf flash games. |
As for story, you could go the silly route and just depict the pigs as a bunch of daffy imbeciles having a good time while the farmer's away.
Further aside, did you know you can put stuff on YouTube and set it to "private to anyone with the link"? You don't have to download it to see it, it doesn't get published and you can delete it any time you like.