Good 3D, but lacking substance.
Teh 3D is pretty well done, and I liked where you were headed with this, but there is a distinct problem here. This is not much of a "Flash" movie per se.
Importing an MPEG into Flash is not what I would consider a good use of the technology. You could drastically decrease the file size by cutting up your graphics within Flash and only using the moving portions of the images (in fact, this is similar to how GIF's are compressed). By a quick estimate, I would say you could cut the file size in half or better.
Anyhow, the 3D looks nice with the exception of a some weird camera movements and the stationary ground in one part.