Shigeru Miyamoto has given an interesting interview to Famitsu - translated and summarised by 1UP - about the design processes behind New Super Mario Bros. Wii.
It's the most closely he's been involved with day-to-day game design in a while, he said. "It's been a nostalgic time for me. I've been getting into the game and making the sort of fine-tuning adjustments that I made with Super Mario World and Mario 3."
Miyamoto says that the decision to go with "a very orthodox Mario" in the modern day and age was "courageous", but motivated by the decision to focus on multiplayer.
"I figured that as long as multi-play was fun, then simpler would be better for everything else, both to players and to us creators. To put it bluntly, I would've been just fine with basically making a multiplayer Super Mario World. That's not too terribly interesting, though..."
The multiplayer served Nintendo's goal of making the game more accessible to everyone without making it easier or creating multiple difficulty modes, since a talented player can carry others through it. "Even if they can't beat the game themselves, it's fun for them to experience the entirety of the game. That's why what you could call the 'story mode' is completely playable in multiplayer."
Miyamoto agrees with us that it's a tougher game than the DS New Super Mario Bros. "I do think the game has a lot more oomph to it than the first New SMB," he said. "World 1 and 2 are pretty forgiving, things ramp up starting with World 3, and it gets even harder at World 6... You could say this game is a challenge to gamers, to see if they have the perseverance it takes."