Paper Mario: Sticker Star spent a fairly long time in development. There’s a reason for that: the game underwent significant changes compared to its initial prototypes.
One of Paper Mario 3DS’ early prototypes would have acted as a conventional entry in the series. But once Shigeru Miyamoto stepped in and tried out the team’s work, he felt that “it was just a port of the GC version.” That would be Paper Mario: The Thousand-Year Door, the franchise’s last “conventional” RPG entry.
It was revealed in the latest Iwata Asks:
Iwata: We imagined rather early on that Paper Mario would be a good match for the Nintendo 3DS, and the papercraft atmosphere of the actual prototype was good.
Tanabe: That was about three years ago, at the end of 2009.
Aoyama: At the beginning of development, we were simply incorporating an idea making use of the stereoscopic display function. Then at the 2010 E3, before release of the Nintendo 3DS, we revealed several images.
Iwata: So why did it drag on until now?
Aoyama: After E3, Miyamoto-san played the prototype and said it was just a port of the GC version.
Tanabe: I had heard that at first Miyamoto-san said that something like an RPG would be fine, so for a while I thought that something like the previous one would be fine.
Iwata: That must have meant that you hadn’t done much that was new.
Tanabe: Right. So we wondered what to do. Then the idea of using stickers came up. Originally, the plan was to use stickers here and there for solving puzzles on the overall map and so forth, but then we thought, “If we’re gonna do that, then we might as well use stickers for the whole thing, including battles,” and we decided to begin rethinking the game mechanics.