That was great! My only complaint is that I do wish the other Sonic characters were there. Of course, I've never seen the opening of "Halo", so I know it wouldn't be authentic. It was great to see all those different Robotniks. They were their own species! Now with "Sonic Boom" there's another one.
It was great to have Scratch and Grounder appear in this serious cartoon. They do set things off quite well. I appreciate you making it just like the game. I assume this is the same audio. The echidnas were their own species.