<p>I'm currently trying to implement a marble maze game for a WM 5.0 device and have been struggling with developing a working prototype. The prototype would need the user to control the ball using the directional keys and display realistic acceleration and friction. </p>

<p>I was wondering if anyone has experience with this and can give me some advice or point me in the right direction of what is essential and the best way to go around doing such a thing.</p>

<p>Thanks in advance.</p>

<p>Frank.</p>

I would recommend checking out XNA Studio 3, it has built in support for PC, Xbox 360 and mobile devices, and it's an official & free spin-off of Visual Studio from Microsoft.
http://creators.xna.com/en-US/
http://blogs.msdn.com/xna/
If you search around, people have written tutorials using physics (velocity on this one)
http://www.xnamachine.com/2007/12/fun-with-very-basic-physics.html