Originally Posted by
Icemage
There's two problems here really:
The first is file size. 25 songs x 30MB average (on the Wii) is 750MB, larger than the base memory on the Wii (512MB), and that's before you even consider any game code.
The second problem has to do with the control scheme. What buttons would you assign to play RBB (it needs 4) that would make any sense whatsoever and be comfortable to play with the standard nunchuck + Wiimote combination?
Looking at my Wiimote, the only setup that would make even a vague amount of sense is using the 1 and 2 buttons for the gem inputs, and the d-pad to switch lanes while holding the controller sideways in your lap or braced on your leg, but that's not a particularly stable way to hold the Wiimote.
Don't blame Harmonix for either of these two problems: they're squarely in Nintendo's court for designing their controller the way they did, and deciding to ship their console with only 512MB of standard storage (part of which is also reserved to the system).