I really enjoyed the video
The whole premise is what made the animation great, then add in the amazing visuals and you have a really great product.
Some things of note:
The narrator's voice sounds a little too nasalized and distracted me on that aspect, but I don't see any reason to take points off for it. I just wanted to point that out. Also, if you were to have a smaller file-size for a movie in flash it would hinder the quality (it'll look like youtube stuff.) You're best bet would be to have the quality you have now, and if you want to have it smaller for people with slower modems, you could try to work with flash's flv player. (sorry i can't offer an explanation on how to do it)