Paper Mario: Sticker Star was a lot of things, but it certainly wasn't particularly comparable to classic RPG experiences like Paper Mario: The Thousand Year Door or even Super Mario RPG. Many fans were left wondering why many familiar aspects of the franchise were left out, and luckily the most recent "Iwata Asks" column from Nintendo lends some perspective into the situation. Some of the responses may surprise you, such as the fact that it was Miyamoto himself that restricted any story elements or new characters.
Kensuke Tanabe, Nintendo producer who worked with Intelligent Systems to design Paper Mario: Sticker Star, comments on the instruction he received from Miyamoto:
"Aside from wanting us to change the atmosphere a lot, there were two main things that Miyamoto-san said from the start of the project—"It's fine without a story, so do we really need one?" and "As much as possible, complete it with only characters from the Super Mario world."
Despite being posed as questions, the development team continues the discussion referring to Miyamoto's questions as "restriction." Obviously they were posed more as orders behind the scenes. If that was all Tanabe had to say on the matter, I'd have understood, though remained disappointed. However, he continues, providing statistical justification for the removal of story elements from Paper Mario: Sticker Star.
"With regard to the story, we did a survey over the Super Paper Mario game in Club Nintendo, and not even 1% said the story was interesting. A lot of people said that the Flip2move for switching between the 3D and 2D dimensions was fun."
It's at this point of the interview where I begin pulling my hair out. Nintendo clearly doesn't hold the history of rich story in Paper Mario in very high regard, but to say that because few found the story in Super Paper Mario interesting is a good reason to drop story all together... well, I have no words.
The restrictions coming from Nintendo inevitably caused the shift in RPG play as well, with Iwata commenting that the team had to innovate as a result of the limitations. And so the Stick System was born, and from there the RPG mechanics didn't last much longer:
"At first, we were making a lot of individual allies as in a regular RPG, but when we decided to focus on stickers, in order to make a clear change with previous games in the series, it was like we started all over again by throwing out the system—including those characters—that we had made up to that point."
Iwata and the team from Intelligent Systems go on to discuss a variety of other aspects of Paper Mario: Sticker Star, from the variety of stickers to the game's Sticker Museum. Mostly they focus on interesting features in the game, and most of the actual design talk is what I've gone over above.
It's interesting to see what sort of direction Nintendo is taking Paper Mario. Were the Miyamoto restrictions due to the limitations associated with being a handheld title? Or should Paper Mario fans from the past dozen years get used to the idea that the franchise isn't interested in story and RPG elements?