More important than the length is the quality, and Shadow Generations is the best Sonic game I've played in years. I'd have ...

Rouge the Bat ... which only featured Sonic until Tails made a brief cameo at the very end. The second one might have made a bit more sense since that's when we got Knuckles.

SEGA and Paramount Pictures released a new Sonic the Hedgehog 3 Christmas short video, titled “A Very Short Christmas.” The short is two minutes long and sees Sonic, Knuckles ... of future characters ...