Incidentally, the bus used by the controllers (maple) actually had support for a second analog stick, but they never released a controller that used it (by which i mean a regular gamepad, there were several novelty controllers for certain games and IDK if any of them put it to use).

Speaking of novelty controllers, SEGA nearly beat Wii to the motion control fad by several years. There was a fishing rod controller and a pair of maraccas that both used motion controls. they also had a prototype of a more general-purpose motion controller which strongly resembles the wii remote but unfortunately this was never released (source: https://segaretro.org/Air_NiGHTS )

If they had just made that their core control method instead of an optional gimmick that only a few games used, history could have been very different.