Keep it up!
That movie was pretty decent, especially considering your age! Don't listen to any of those pricks who are bashing your work. You made this movie to express your self CREATIVELY, while people like LordVenom and Anywien (who have not, might I point out, ever even submitted any Flash of thier own) express themselves by being dicks. Take this piece of advice... Usually the most rude and obnoxious people you meet online are the most pathetic groveling self loathing losers in real life. There is a reason they would rather site alone at home and type mean things about people than to go out into the real world and say rude things to real people. And in the meantime, you keep making your Flash movies. If you are this good at 11 (or 13, or whatever), you have great potential!