Some (hopefully) constructive criticism
Okay, It's the first of August now, so whether or not you'll even read this I can't be sure of, but here's what I have to say, take from it what you will.
First off, the sound quality: the music was alright, and went well with the theme, however, as others have said it drowned out the narration and either needs to be turned down, or you need to increase the capture volume on your mic. Also, what program are you using to record the voice work? There are some good free ones floating around the internet (that DON'T have those fun little viruses either). And as far as the quality of the mic goes, well you can get a decent one for around thirty to forty bucks depending on where you shop. That said, I believe you did a good job with the actual narration, you (I assume that's you) keep a good tone and inflection going and stay relatively in the mood of the given situation, which is good.
Second, the art: this isn't really what you would call an animation, it's more like you made a slide show with a story, which in itself isn't bad if it's presented properly, however if you intend to follow that route I suggest you actually draw the pictures freehand on paper and then scan them in if you find digital work to be to strenuous, or if you lack the proper software and hardware to do it.
If you really want to make animations, however, I suggest you look around the web and check out your local library for information on the topic, as well as the technique. Flash offers animators a lot of time saving features over the old frame by frame drawing method (ie, drawing 120 to 240 individual frames for only ten seconds of motion), but it still takes a great deal of time and dedication to do it well.
On the topic of doing things well, your writing and grammar need a little work. This is not to say that you don't present a potentially compelling story, because you do, however; some of the mistakes that you make are very basic and could easily be caught by either rereading your scripts yourself, running them through a word processor's spell check, or having friends and family edit it for you (I personally recommend doing all three). As it is there are several distracting errors in your work that are very easy to spot and fix and which detract from the quality of the piece. What's more the story seemed rather short to me, as if you ran out of ideas and decided to just cut it off. This may not be the case, but that is how it seemed, and I felt that you could have put a great deal more content into the piece without it seeming to long or drawn out.
Finally I would like to say that the situation of your story is teetering on the brink between cliché and convention. It hasn't fallen either way just yet, as there wasn't enough material to really send it down one path or the other, but any future writing would be well off to have had such taken into consideration. Originality is the light of life, after all.
Now, I understand that you're only thirteen, and that this is your first flash on NG, but using those facts to explain away errors and shortcomings will only be looked on as excuses. And they are excuses, so don't fall back on them, or you'll never progress as an artist or a human being. Just because you're thirteen doesn't mean it's acceptable to only go half way. If we expect from you your very best then you should accept nothing less yourself (note that we don't expect perfection, that would be a lot to ask [well most of us don't anyway]), if not for us for your own satisfaction.
But I digress, and I'm running out of characters. Regardless, please feel free to contact me via private message if you have any questions or feel the need to rage at me. In the end you get a three from me, because I feel you can do better. Don't take my low score or the low scores of others as a deterrent, an artist needs a thick skin, after all, and if the people say the work is no good heed them, though take their words with a grain of salt. Keep at it, I expect to see more from you.