In a talk at the Game Developers Conference, Animal Crossing: New Leaf project lead Aya Kyogoku admitted that Nintendo played it too safe when it made the Wii game, Animal Crossing: City Folk. Following the success of Wild World on DS, he says, the company stuck to the formula too much.
“We were too afraid to consider changing the formula," Kyogoku said, as reported by VentureBeat. "As a result, we mistakenly stayed the course with [Animal Crossing: City Folk], even though this was the time to make changes."
City Folk did decent sales, but it wasn't the breakout success of the DS version, and critics often dinged it for being too similar to the GameCube and DS versions. At that point, Kyogoku says, the company started thinking about how to make the next game different.
“Animal Crossing is a communication tool," he said. “In that sense, I think communication in Animal Crossing can help harmonize communication with people in the real world." To that end, the team set about taking advantage of social media, like giving players the option to use Twitter and Facebook to share patterns, or using the Miiverse and Art Academy Sketchpad applications.
It seems to have paid off, since Nintendo also recently revealed that that New Leaf has sold 7 million in just over a year on the market.