Why are they even making a Sonic game with this in it? Out of everything they've done to this franchise that just does not fit, this in particular is like trying to jam a basketball through one of those little red stirring straws you get for coffee at McDonalds.
For those not in the know, despite Sega trying to play it up as a secret (something they continue to do in this teaser), it's been known pretty much since day 1 that something happens to Sonic in the opening cinematic, where he appears to be caught in some sort of machine Eggman built to rip the Chaos Emeralds out of him while he's transformed in to Super Sonic. Some of the first images released (aka: leaked) showed Sonic standing next to a hairy, hulking, shackled beast looking on from the dimly-lit shadows.
There's been a chart that's cropped up several times as a joke regarding people's feelings towards new Sonic games:
Ladies and gentlemen, welcome to stage 2 of the 3 stage cycle. You may remember our friend, stage 1. Please make sure your seat belts are connected and your tray tables are in their full and upright position, we will be entering Stage 3 in the coming months.
Thank you for your cooperation.