Well, when Mario hits Luigi with a hammer, Luigi goes underground, making him hard to hit. When Luigi hits Mario with a hammer, Mario shrinks, making him easy to squish.
Plus, Luigi uppercut a ROB to the moon in a battle against the PSP. I haven't seen Mario do much of anything against it.

Where are these lemmings going? The
Super Nintendo Super Shire! Hop in line and follow them there!
[ June 08, 2005, 08:05 AM: Message edited by: CodieKitty ]