I should hook up the GameCube and try it again. I remember the physics being more janky than the adventures and punching with Knuckles or Omega was just asking to go flying off a cliff. Also all the combat was less interesting than the platforming of the adventures. The late game enemies with the helmets you had to knock off and then try to hit their tiny weak spots sucked. But it was still fun sometimes.
If I were to hook up the GameCube again though, I'd probably just play SA2B again instead.