In my book, Mario games other than Mario Party are pretty much core games, as are Zelda, Metroid, Pokemon, F-Zero, etc.
Or was Nintendo doing blue ocean audience expansion during the NES days? No, core games can bring people to a system, too, and expand audiences (so yeah, they're also bridge games).
What's new about the Wii vs. GCN etc is the move from Mario-type games as the salient concept to balance boards, vitality sensors, Wii Music-type stuff, etc. When it hits, it hits big time because the potential audience is huge, but in the meantime they should be bringing more Mario, F-Zero, etc, games which would together drive sales significantly in a demographic that spends a ton on games.
EDIT: wow, I see that you define any game with legs as NOT a core game but a momentum game. Discussion over. That is ridiculous.
