Sonic: Needs to cut back on the platforming. The sense of speed is what Sonic was always best at, and the game is like playing a rollercoaster when you get that speed going. As soon as you stop-- because you hit spikes, or a wall, or you have to play the "platforming" parts of the game-- it becomes awkward and dumb. If the game is about speed, don't make me wait for a moving platform that is slowly sine-waving back and forth. Or at least let me jump over the whole damn thing if I'm going fast enough.
And Dr Wily final form? That's easy. He's weak to your stupidest, lamest weapon. Always.
I wonder if Sonic would be better without obstacles like spikes and instead have fast moving ones like the flying Robotniks (and that fast running one from Springyard Zone, even though he was annoying to kill)and maybe flying traps. Differently wouldn't remove the platforming though.