There are a handful of Holiday themed games hitting the Windows Marketplace and you can add Ring Ball to the growing list.
Ring Ball is a simple game where you have a ball that changes colors that you use to collect matching colored rings. Ring Ball makes use of your Windows Phone accelerometer and you roll the ball around the screen by tilting your Windows Phone this way and that. You collect rings of matching color to earn points, while avoiding non-matching colored rings.
Once you collect a ring, the color of the ball changes. Should you make contact with a non-matching color ring, you lose one of your three lives. There are bonus items that pop up from time to time such as the psychedelic rainbow that allows you to collect any ring, regardless of the color.
In tinkering with Ring Ball it comes across as an entertaining game that will test your skills of balance. My only nit after spending a short time with the game is that the ball movement seemed a little sluggish. Unfortunately, there isn't any settings to adjust the accelerometer's sensitivity.
There is a free trial available with the full version of Ring Ball running $.99. You can grab it here at the Windows Phone Marketplace.