First try!
This is very good for a first flash.
Just add a preloader. There's loads of tutorials for 'em in the NG.
And it's 5 megs?! You didn't compress it, though. The ending music was probably 128kbps or so. What it should be is 56kbps MAXIMUM.
I know it'll sound shit, but it's supposed to. I probably loaded this flash longer than it played. And that's not supposed to.