There's actually this thing called "The Sonic Cycle", which shows the cycle fans go through when a new Sonic game is announced. Sonic Generations broke the cycle because it was well received by fans, until people started complaining about how Sky Sanctuary isn't yellow or how the Sonic 1 port was horrible (the Sonic 1 port was a BONUS in the game! They complained about it despite the fact it was a little addition for when you finished the game! )