Not too shabby!
I've always found these types of games to be really neat and I have to say that this is a pretty solid start if this is your first. It's obviously not the best use of a webcam, but I like the ideas it presents and it looks like it could have potential. If you could improve the graphics and maybe add more songs (From the Audio Portal, perhaps?), I think this game would be great.
Hope to see something of a sequel from you in the future!