99 Lives
During game play, pause the game, then press L,Y,B,B,A,X,Y,Y,B,R. Counter will still say 9 though.
Level Skip
During game play, pause the game, then press L,X,A,Y,Y,B,R to warp to the end of the current stage.
The Genie has more
Tom and Jerry Cheats at CheatingDome.com.