Really cool for a first animation, I found it smooth and easy to watch, I really like the sound effects as they were really fitting to the visual. Look forward to seeing more content from you. ;)
Reviews for "My first Adobe flash animation :D"
Rated 0 for the portal because this is an awesome thing to show off in the forums, but not really portal-worthy. You should consider making an animation thread in the animation forums.
With that said, my review rating is for the content itself. For your first animation in Flash it's pretty smooth. I don't know what kind of background you have, but your motions were believable most of the time, and that's pretty damn good for your first shot. Keep at it.