This is why I'm in favor of the Adventure games. In short, there's noticeably more emphasis in how much coordination the player has over Sonic, and all the other characters in the Adventure games. The terrain is more "open" and the game is more interested in the player's activity. It is more organic and free.
Precisely why I'm in favor of the Adventure game, too. But, as far as frameworks, challenges and developers' efforts go, they can bend the player's interest. That's where fun is created and becomes kind of objective or at least out of the common thrilling sensation of a rollercoaster ride. For example, if you hide an object and make it so that one would only find it going out of his or her way and somewhat by chance, the fun in finding it does not depend on the player's interest, only in the momentaneous feeling of uniqueness and displacement.
Like the statue in Wacky Workbench.
But anyway, "fun tricks" like these can be done easier with the Adventure style. Generations can obviously do that, so much so that it did, but it doesn't look like the game was made for this. There is this video DarioFF has posted, sure is interesting and shows potential, but still feels like it would be much harder to put elements of risk vs. reward in an environment like this. Not only because of the boost, but because it feels like Sonic would be completely unable to focus on a point of interest due to his moveset and speed.