Tetris + Mario + wireless multiplayer + wifi = probably can't go wrong. Woohoo!
Maybe the Boo steals one of your opponenets' saved Tetris blocks? I don't know what else it could be. Maybe just a distraction thing like lots of Boos flying around the opponent's screens.
The only thing that bothers me about Tetris is the ever-increasing number of blocks given to you in the "next" queue. Original Tetris only showed one. Recent versions give you four -- some with a "hold" box for you to store that long skinny block. Now you get six?! How much easier can you make this?
I agree with that. But if the blocks move really fast then it would help a lot to see that far ahead. And maybe you can choose to have less previews than that on harder modes.