XML features, where there's not necessarily any corrolation between elements
of different graphics. This didn't work well, anyway: it'd apply the old tweening
queue to the new graphics, but they might have completely different animations.
This will cause transitions between NoteSkins to be more abrupt, but we don't
use that feature anyway.
Have gameplay objects hold a PlayerState pointer instead of a PlayerNumber and indexing back into GameState.
This will simplify off-screen players (e.g. CPU ghosts, network replicated human players, >2 players using one NoteField)
Glenn Maynard