There was this one thread in which platformers were being discussed really in depth. Specifically Sonic platformers in 3d, and I think I have an idea on how to fix the combat while adding to the platforming. Why not, when you destroy more than one enemy by jumping on top of them, the camera changes to bird's eye view?

This COMPLETELY does away with the shitty auto aim mechanics we see in 3d Sonics without compromising jumping speed like in the 3d Mario, Pacman or Crash games.