Sorry in advance if this is old.
While playing Brawl, I decided to experiment with some of the items. The Pitfall item, in particular, has an effect that is not stated in the manual or the official website for the game (smashbros.com). If you hit an opponent who is in the air, it sends them spiralling striaght down. It acts as a meteor smash. Remember this only applies to opponents that are in the air. If they are on the ground, then what's in the manual and smashbros.com will happen.
Interesting, don't you think?
Yeah, I did notice that. It's very interesting, but considering the "earthy" nature of the item, I suppose it's not that suprising that it would send you down to earth.