BELLA is a discontinued Hetalia RPG created by MandyHanazuka. There used to be a demo available for download, in which you could explore various maps, however, it was taken down when the creator decided to discontinue the game.
As it isn't a well-known game and the creator never revealed her plans for it, the game remains obscure.
The creator has also moved accounts, but failed to mention to where.
From the title card, it can be assumed the RPG was planned to be set in the Nyo!talia verse or at least, involve Nyo!talia.
Either way, it would have been the first Hetalia game to feature the Nyo!talia cast and not just a few of the Nyo!talia characters.
The game page can be found here.
Edit: I'm so sorry to put an edit on this, whoever made this, bless you. I didn't know BELLA was going to get any recognition. So just to set things right, the story was just something strange going on, one by one they were changing, their lives as they knew it was changing. They didn't like the change, really wanting to return to how they were before. I completely forgot what I was planning to do with it altogether.
As for the moved accounts, I had a post about it, but had to erase it due to harassment issues and avoid them attacking my new account. I have a doodle account now, and a random account where I will probably post new games. If a link is needed it's http://suomentasavalta.deviantart.com and http://marrionettamaestro.deviantart.com/