Nice game. Pretty hard but fun :)

Nothing too new, but it was nice. I spent a veru good moment.*

Just a few ideas :
- add an Undo button
- give achievements and medals for given numbers of stars reached (especially, a 100% medal for 3 stars on every level)
- maybe you can indicate the maximum number of moves for stars during each level ? for instance, if you have to do 60 moves or less for 3 stars, 80 or less for 2 stars, 250 or less for 1 star, my number of moves can be indicated as "Moves : N / 60 ✰✰✰" as long as I'm under 60 moves, then "Moves : N / 80 ✰✰✰" as long as I'm under 80 moves, then "N / 150 ✰✰✰".

"Nothing too new or interesting"... I've seen this kind of game a lot before, but it was cool of you to put a Christmas spin on it so I could have some puzzle time during the holidays.

I'm not sure if I'm just an anomaly, but I didn't find this too terribly taxing. Maybe next Christmas, you can release a level pack with some more fiendish levels I can swear at...

The game is really challenging, but it's now freezing at 100% while loading.

Not too bad, a medal for 2 or 3 starring every level and an undo button if you make one or two mistakes are a few things I can think of to improve on the game a little.