Brilliant!
A magicians success always comes from his/her's performance. You had the challenge of presenting this as a form of an interactive flash media. I got one thing to say about this: brilliant!
I did, however, noticed a flaw with this magic reveal, and it had to do with the "Again?" button. It's not that it has a technical problem, or that it is a sort of an eyesore, but it is rather its presence that is the issue. Usually, a magician only shows his/her tricks once. This "Again?" button somewhat defeats this golden rule.
Although it is true that the trick could have been ruined anyways, primarily because it is presented as an online interactive content, but the absence of this "Again?" button could've prevented a number of users from ever figuring out the trick.