As far as I could understand your English, you already know how to play SWF.
Anyway, this is an article on the topic:
Stream YouTube Videos in WPF[
^].
Now, you can have any peer
Control
s or
UIElement
s overlapping you player control (e.i., childen of the same parent but on top of your control).
Finally, I don't know your purpose, but the design idea looks crasy. Any busy backround is very distracting, and animated even more. I would highly recommend not doing such things. If you show animation, it should be in the center of attention. You choice though, may be you have very different and interesting idea...
—SA