I got my first "game" finished today. I added a WebService to the project, to save scores in an XML file. As this is my first Silverlight project, it is very bad/ugly coded and structured, which is why I won't publish the source code for this.
The gameplay is very simple. You need to pop (by moving the needle into the bubble) as many bubbles as you can within 30 seconds. You don't need to click to pop the bubble, just move the mouse(needle) over it.