To complete current mission, pause the game and enter this code:
Hold R and press B,B,B,X release R, Hold L and press Y,Y, release L, hold R and press B,B
To get sword upgrade, press start to pause and then enter this code:
Hold L+R and press X,B,X,Y,Y,B,X,B
To unlock Big Heads, press start to pause and then enter this code:
Hold R and press Y, Y, Y, Y, release R and HOLD L and press Y, Y, now HOLD L+R and press Y, X, Y