Hey Thanks! Well, you have a nuclear bomb inside the snowball. Hadn't enough time to introduce that in a intro. Doesn't make so much sense, I know, but I liked the gameplay-idea.
You're loosing snow, when rolling on a normal ground, or hitting too hard on the ground (If you have a long fall for example) and collecting snow, when rolling along snow-areas. That's the core mechanic. You always have to have a look to your snowball size. You're heating up, when you havn't enough snow too keep the nuclear bomb inside. :D