This is really good stuff, Salnax. One thing that damages the reliability of your findings is the relative success of Wii and GC in the various regions. The GC sold much, much better in NA than Europe but the Wii was closer to even. Since GC saw releases of more "core" titles (while Wii-type titles didn't exist yet), the added consumption of those titles in the US would imply that they are larger consumer of core titles when in fact they were just larger consumers of Gamecubes. I think you see this in the difference of 2D to 3D Mario titles - NA has a greater share of the 3D titles, but that is likely because there was a 3D on GC but not on Wii. The impact on Mario is minimized because Wii sold much more than GC, but it could lead to variances of around 10%. With titles that didn't see release on Wii or GC - or just one title on either, the impact would be much more.
You could argue that Wii sold more in Europe BECAUSE of the casual titles - and that's true to some extent - but I would hesitate to draw conclusions of NA audiences liking the core titles more. I think its more a case of North Americans willing to buy Nintendo machines and hardware regardless - especially the core titles - while Europeans only buy Nintendo if it is the "it" thing to have.
