This happened to my best friend last night and pointed me to this link when he did some research. Just passing it along.
Originally posted by ArticleUnfortunately, gamers eager to sample the cel-shaded beat-'em-up were in for a very nasty surprise. That's because the demo contained a glitch that will erase all saved games on the memory card or cards currently inserted in the console.
I finally got my copy yesterday. I have to admit something - I'm sort of an electronic football Hail Mary junky. I generally switch between 3 basic plays - Screen Pass, strong side rush, and bomb. I suck at completing passes right now.