It got cold and it started snowing under the mountain!
You might also get a new achievement if you "fight" the snowman.

Full list of changes:

• Snow area, with a new achievement, photo, snowballs and falling snow
• Option to enable snow mode for the whole game (after finishing the game once)
• Fixed dog getting stuck if he can't poop
• Dog will poop more if he eats things
• Added a close button to the snake minigame
• Some gamepad mouse pointer tweaks
• Some typo fixes and text tweaks