I’ve now played a Sonic game for the Xbox 360. Right off the bat, this game does not feel like a Sonic game.
In Sonic games, you start the game, and you start playing. At most, you choose a character (Sonic, Tails, or Knuckles) or load a saved game. Then you’re racing through the level.
There is a story. (e.g. Dr. Robotnik has trapped your woodland friends in badnik robots and is trying to collect the six Chaos Emeralds in order to rule South Island.) There’s just no exposition.
The 360 Sonic starts with a (much too lengthy, IMHO) exposition movie and then you...walk around a town talking to people.
This post was somewhat inspired by We can steal the term “neo-retro”; there are parallels in P-n-P gaming and console gaming.