Forgivable for a first
Not a bad animation, and certainly had some cool flashy effects (very much like). Unfortunately, it suffers from many common fanfiction issues. Why do Zero, X, and Metal Sonic all have black armor? Why did Sonic become the Matrix? Where's that DAMN fourth Chaos Emerald?
To be more clear, this suffers from reeking of things that a young teenage boy thinks are "cool", like characters dressing in black and swearing. Robotnik and Sigma's meeting was very odd and poorly set up (Robotnik was just running through some hallway. Why? To where?) The fight scenes were flashy and fast-paced, though the choice of music was, eh, about 50/50. It seemed divided between nice music from the games and "hardcore" rock. Also, the track from the intro to Sonic's second fight looped VERY noticeably.
Speaking of the fights, the first was good, had no real problems with it. The second, however, while opening with some pretty awesome fending off of mooks by X and Zero, really bugged me once Sonic arrived after his big power-up. The guns were completely out of nowhere, not to mention out of character, and the reactions of the Mavericks seemed odd. The fire bird (sorry, his name escapes me atm) seemed very, VERY afraid of Sonic suddenly turning yellow. I understand it was a power levels thing, but there's ways to clarify that a bit better. The main problem is, of course, the one-sidedness of the fight. Yes, watching Sonic stylishly beat the crap out of baddies is more than a little fun and cathartic, but having a fight where the villains pose no threat is inevitably just boring. A good fight features an impressive display from both sides; it adds tension and makes the victory feel that much more rewarding.
Despite some pacing and plot issues, and quite of bit of room to improve in the writing, I see plenty of potential, and I'm sure the following episodes will be more impressive.
