First difference: Mega Man X has 100% more X's in the title.
If at first you don't succeed, destroy everything.
Oh my god, they're back again.
Hey sci-fi writers, is there any chance you could invent a giant space corporation that's just kinda chill?
The Blue Bomber and about 2 billion Robot Masters square off in this fan made homage to the "Mega Man Gigamix" comic series.