Good day, community.
This is an idea that I've been having since quite sometime now, and since Luigi has always been my prefered character in the Mario franchise, I wanted to ask if there is a possibility of hacking the SM64 rom to add an option to play as Luigi in Super Mario 64.
I know it is possible since SM64: The Missing Stars adds an option that allows you to play as Luigi by pressing D-Pad left, and then going back to Mario by pressing D-Pad right.
Now the thing is:
1) How difficult would it be to include such feature in a normal SM64 rom? I mean to be able to play as Luigi in NORMAL, unmodified stages, not the ones from Missing Stars nor any other modified levels.
2) Could a custom SFX sound be implemented for Luigi so he doesn't use the same SFX sounds as Mario?
3) In the case in which it would be TOO difficult to include an option to add Luigi from scratch, could it be possible to modify the levels from a Missing Stars rom and changing the layouts again so the stages are the same as they were originally?
Please, let me know of any tools that could help to achieve such thing, or if there is a hack that already does this, let me know too.