Seems easy and typical. It's not! First, you must avoid the barnfires - obviously bad for a snowball. Then you have to avoid the shooting comets that can come from any direction. Water balls also fly across the screen; they slow you down temporarily if they hit you. Same for the flying dirtballs.
There are 60 levels. At the moment I've done the first 47 levels. This is surprisingly fun. My only qualm is when you die: the screen image shakes violently.
Yesterday, when I woke up, the first thing I did was play this game. High praise indeed.
Lookout Blizzard quite possibly makes it onto the list of Best Puzzle Apps of 2012. That list will be revealed on New Year's Eve.