We experimented with getting the fabled "4P" shadow working.
This is just getting the player structs to behave and the controllers split up.
Unfortunately spawning 4 players is causing weird NaN camera behavior, but spawning 5 players works... Still figuring that out.
There is a LOT to do to get multiple screens, and even then it will probably run awful. So don't get your hopes up on this. It'll be interesting to see if we can even make a 4P battle mode as JMan wanted.