When Nintendo 3DS was first revealed, a new Paper Mario was announced as one of its first titles. At the time the first Paper Mario entry on a handheld, it was simply known as “Paper Mario”, and a trailer was shown on trade shows like E3, but never published officially.
Nintendo went silent for a couple of years, until it resurfaced as Paper Mario: Sticker Star and launched in late 2012. It was recieved with mixed to positive reviews then, but now is widely regared as the weakest entry in the whole Mario RPG subgenre.
Fans were saddened because, based on the little off-screen footage that was known from E3 2010, that first trailer looked really different from the final game, being closer to the traditional turn-based combat from The Thousand Year-Door than the puzzle-solving of the final game using stickers.
https://www.youtube.com/watch?v=hKdcu5g0lfc/
And now, for the first time in more than 14 years, the trailer for that Paper Mario 3DS prototype has surfaced online. It has been posted on YouTube by usar Marionova, and it is unknown how this trailer has reached the web.
Recent Paper Mario titles like The Origami King have been received more favourably, buy Sticker Star remains as one of the few “grey sheeps” within the Mario franchise. It was revealed in the Iwata Asks interview that it was Miyamoto the one that requested Intelligent Systems to simplify the story and only use existin Mario characters, and give more context to how that original prototype -never before seen with such detail- was changed into Sticker Star.