If Sticks and the secondary characters wasn't enough to fill you up for the game, think again. Nintendo Life just indicated that the developers of the game could be adding many of the fan's "favorite characters" into the game. While continuing to keep a balance between Sonic's new changes and the history that makes it. Bob Rafei told GamesTM that:

We looked at the rich universe and history of Sonic and began to gravitate towards characters that best fit into our objective to make an epic adventure game. Dr Eggman was a very fun character to explore and created a really fun dynamic to Lyric's straight man super villain vibe. Also there are two fan favorite characters that we're excited to add.

Although there has been some controversy of Knuckle's redesign, he also stated that it was done to make Knuckles as more of a "Power-based character". So just to make sure, this game will offer a mix of the old stuff and new to the game, which could give some people some odd reminder on why they're in the game but still, many would be happy for it. So the character could be tough to think about but we don't know who'll be soon. Could it be Shadow, Silver, or anyone from the original Sonic Franchise? Well, we'll have to wait and see about that. And as always, keep it locked to Sonic News Network for the latest on Sonic Boom and more.

UPDATE: After months of Speculation and just recently, SEGA has JUST CONFIRMED that Metal Sonic and Shadow will return to Sonic Boom. There's no word on what version they will come officially (though Speculated Metal Sonic could come to Shattared Crystal).