Well, Unleashed was a step in the right direction. Just switch out the werehog for Knuckles, and there you have it..
The reduction of new characters was also in the step in the right direction, don't forget that
it's Shadow's fault 6 new characters is a few too many when they introduced Rouge, Shadow, and Big (Along with Blaze, Silver, and Marine with Chip and Cream the sidekicks, the Chaotix, hell.. even Bark, Bean, Tiara, Fang/Nack, and the two unused characters Tiara and Honey (Wonder where Mina and Ash Mongoose came from..) could make good modern comebacks).
I apologize for this, since I don't know if adding 12+ Characters to a series that's standalone with Sonic, Tails, Knuckles, Eggman, Amy, and Metal Sonic was the best thing for the series... Could've gone the Mario route with the RPGs, but eh, who knows?