Rock of Ages would roll out an update to celebrate the holiday season. The Steam version of the game has received a free update that adds some festive new options. First and foremost is the snowman skin for your boulder, which you can see above. The update also permanently unlocks every defensive unit in the game and "introduces a number of limited time interface changes."
For those who haven't pick up Rock of Ages just yet, the game is currently available for $5 on Steam, half the usual price. It's also featured in Steam's Awesome Indie Bundle, which gathers together ten games, including The Binding of Isaac, Jamestown, Blocks That Matter and more – all for $20.