SH: Yeah, I was going to say that Knuckles and Omega are the same.
The teams spread out in the same way, the hit detection is already sloppy, and
it shouldn't matter that Omega is around a foot and a half taller.
(Like I said, the hit detection isn't totally accurate, and the spheres are on the ground, anyway.)
Shuffle: (Remember, I haven't played it, but I'm familiar with the Mario Parties.)
If a 4-player game can be done with one controller, then maybe dummies could be allowed
(I mean, some games need 4 controllers for the 4-player option to appear.
Others allow the controller to be switched between players to get the game set up.),
but I'm thinking that it might be best to allow any difficulty, as long as it only affects
computer-controlled characters, and not other things, like Mario Party 2's jump rope.
Of course the easiest level is what would be used. If there's a reason to use any other level,
then that would require a rule. ("The Easy level must be used.")