For a first game: Not bad. Not original.
I haven't pong in a long while, so I'm glad you could submit your version of it. However, it is not unique, and it is very similar to the original pong. If you added more originality, added some more features, it would be great. Good first flash though, that is pretty good. I'm sure your still learning, so keep on learning, and your work will progress as you work. Good job!