you know get over yourselves people, any game given the right mechanics can be good, (and vice versa). If they did make a sonic sandbox, or an online sonic game, there is no guarantee that it will be bad, heck Sonic Team may come up with a miracle but don't doubt it before you play it. Games haven surprised us before, look at Kingdom Hearts. It was the worst idea known to video game history yet it worked, very well, why because it was handled properly.
Fat plumber saving princess
Donald Duck and Cloud Strife in the same game
A kid catching Monkeys
A guy fighting aliens and at the end being revealed female
An ocarina being a key element a game
A lego version of Batman
A gun that only shoot portals with a psycho robot offering cake!
All these ideas when stripped down to the initial thought are Stupid yet they worked very well. Don't knock it till ya try it people