It's nice to play games you don't have to download and install. I also managed to get myself on the high score list too, w00t
Overall, you're off to a good start with Silverlight. I have some suggestions and tech tips you can use to further your game dev with Silverlight.
Skin your UI! The default Silverlight styles are yucky. From an organizational standpoint, I would personally recommend that you make use of ResourceDictionaries to manage control styles.
You can change your splash screen to display something more related to your game while it is loading.
Some background music would help set the mood. Incomptech has a couple good free tracks. Just make sure to credit him cause his work is fabulous and he does it for free. Mad respect for that guy.
For fun, I downloaded one of your games and could read your code. While I won't critique your coding (hehe), if you want to protect your IP you should obfuscate your assemblies. Obfuscar is one of the best free, lightweight ones out there.
If you want some other tips and advice, drop by our forums and ask.