Alright, goaded on by "Sonic doesn't need a story" and the repeated rant of "Why don't you do better", I've decided to compile a fair set of knowledge in the sonic universe for what a sonic game should and shouldn't be.
I figured if I'm going to give this a shot, I'm going to need a lot more knowledge than what I have, and hopefully with subjective/objective backing as well.
Also, this could be for laughs, or for pointing out variuos shortcomings of games... I didn't see anything else like it, so here we go.
Problem: Sonic moves too fast for accuracy, or too slow for enjoyment (SU/S06 "walking" for the first, Werehog for the second)
Solution: Spindash (SA/SA2 is a perfect example of this. I can imagine this as part of the developmental stages of S2 as well "We want sonic faster... oh shit, now he's too fast... oh, spindash!")