Speechless...
Extreme high quality, superb soundtrack (whoever they are), detailed drawings, high frame-rate, great pace... everything in this flash in PERFECT, really.
Of course, I have my own preferences on it (as, for example, why you keep the Eggman from the cartoon series, when you could have evolved it into a more serious one; why there's no real new character watsoever, and the fact that the story looks like a very well written Sonic standard plot, when there's potential for a real Sonic evolution (not present on the trailer)). The action is there, and it's great, but still, this quality deserves a more titanic story, at least on my opinion.
Something that defies everything we know, or seem to know, about Sonic. That's what this movie should be about.
But, still, the flash is great. Hope you release the complete thing soon.