Superb.
Absolutely great. LOVED the guitar mix of the chemical plant zone and stuff, Really well made, good story, although a prequel would be good? (unless you've already explained somewhere else how tails died)
Just a few problems, but nothing crucial:
Just a typo in the intro, and where did those trees go ? :S
Anyways. Never mind, because the flash overall was great.
Well done, keep it up :)