This has a perfect winter theme! It reminds me of the touchscreen minigames on the DS.
Everything felt quite good! Some feedbacks:
The melting circles that melt your snowball faster do not look particularly dangerous, so it took me some time before I understood they were melting me faster when on. Perhaps a pixel smoke animation could help with this!
Since the snowball is not always centred, grabbing it while it is rolling (which you almost have to in some levels to get to a safe place fast enough) is extremely difficult at the moment. I would recommend either keeping the snowball in the centre of the screen and instead doing a nice rolling animation that reflects its direction or allow the player to click and drag from anywhere! I think option 2 would be easier and would make this game very easy and fun to play on mobile.
Sometimes the snowball felt that it didn't go in the direction I set it to, but perfect physics is absolutely not something to be expected during a game jam.
I really enjoyed the level where you could wait for the snowball to become a certain size to go through a secret way. I think more levels that use this design would be fantastic! Maybe you could also make levels where you have to pick up snow to become gigantic and roll over enemies/things in your way.
One more thing, you should "catch the mouse" for this game, as if you go outside the window, the game stops working. If you catch the mouse, you could stretch the band as much as you want.
Overall spot-on with the theme, fun gameplay and the music is nice, too! Consider working on this some more, I think you could release it!