Ummm... hello? How do you know it's wireless multiplayer? If you guys haven't noticed, all the characters are standing around eachother in those screen shots, so for all you know, the other characters could just follow you around and each button (A,B,X,Y) makes each seperate character jump.
Do the Mario! Swing your arms from side to side, come on, it''s time to go do the Mario! Take one step, and then again, let''s do the Mario all together now! You got it! It''s the Mario! Do the Mario! Swing your arms from side to side, come on, it''s time to go do the Mario! Take one step, and then again! Let''s do the Mario altogether now! Come on now! Just like that!