One step closer to the thrilling conclusion...
Ah, yes... I can just FEEL the action heating up! You've done a BEAUTIFUL thing with the story so far, and to me, story is a major part of making an epic like this so good! Animation was perfect, the pixelation served its purpose, the newly added element of Shadow being there, the action-filled battle, and the effects... Oh, all the GLORIOUS effects you've done with everything! This is one very high-quality movie!
However, like most movies, this one STILL has its flaws! For example, there were some spelling and grammar mistakes. Proofreading your work before submitting it easily remedies this. Also, I absolutely despised how the text for each character talking was so often cut off! I suggest making the textboxes bigger next time and having about 2 or 3 lines in it whenever someone talks. That way, what they say won't get cut off unless it's a really long sentance! Headshots were fine, however, the voices seemed kind of distracting, so I'd advise that you totally remove them next time to make it better. Since the headshots make it obvious who's talking, there's no need to worry about using the voices to keep people from getting confused.
Lastly, the bittages... Everything was 16-bit except for Ridley and his monsters (those are from Doom, right?). That is the only major problem with this movie's animation, as sprite movies look a bit strange when the bittages are mixed, even if it's minimal. Also, Onslaught was pretty big compared to the rest, and his fighting game-style sprite clashed with the other platformer game-style sprites However, you did a suprisingly good job of using him to avoid the clashing from being too harmful to the overall presentation, so it won't really hurt you like the mixed bittages will.
All in all, I simply cannot wait to see the end of this movie! Will the souls of Sonic's friends help him achieve his ultimate victory? Will Sonic's sword mastery be enough to slay all of his enemies? Will his allies just sit around and watch him save the world effortlessly with their jaws dropped, gawking at his hyper form? Or perhaps they will join together and exceed even Sonic's power to win? I don't know what's going to happen, but I'm going to LOVE seeing what comes out of all this! Great job, man! This deserves to get front page, whether or not it actually does!