Not the best I've seen...
For one thing, your graphics need serious improvement. I couldn't tell if that was a car or a funny looking bike at the end, and most of the other drawings were pretty crudely drawn. Perhaps using the paintbrush tool for characters and line tool for furnature, buildings and other stright objects might be better than relying on the pencil tool. I know drawing with a mouse can be hard at times but I've seen plenty of good Flash work that used a mouse and still had pretty good looking drawings.
I really didn't understand the storyline either. Some guy leaves Africa and then goes to Atlanta, and then what happens after that? Also, I found it odd to a put a piece of Elton John's "Rocketman" right in the middle of the Flash for 4 seconds for really no good reason.
Your FPS could have definitely been higher as well, since it clearly seems you're running it around 12 when it should be around 20-30 if you want smoother animation. Some of your airplanes and "cars" were running pretty slow and were even skipping at that slow rate.
Make your FPS higher if you're going to have a lot of animation, definitely put in more detail and work on the graphics. If you want something to look like a car, at least look at a picture of a car while you're drawing it. Believe me, it helps. Get some good voiceovers for your characters and you'll be well on your way to making a really good Flash.