If you want the simple awnser you need to hold L and R triggers while loading a file and your player will be Luigi. Today, I was playing normally, like so. But when I looked at my character it was Luigi. After 3.1415 million years of invesigation I stumbled over it again, and again, and again. Finaly, I found it! Luigi plays differently. especially in 4-4 I can speed run it in 362!