Cozy little game. The level is made well, and the audio also helps sell the idea that we are on a winter landscape. Pretty cool!
Minor things:
I accidentally made a mitten spawn out of bounds, and I could not pick it up (I made a snow angel at the left side of the level, near the dry tree). Luckily for me, it turned out that it is possible to get more than 10 mittens spawn, so I was able to finish the game without resetting.
I felt like occasionally the angel minigame was a little too quick (because it started right away when I clicked E, and it was a faster version of the minigame). I understand this is part of the challenge of the game. However, I think adding just a slight delay before the minigame pops up, or adding some sound effects (when the angel approaches, or when the minigame shows up on the screen) would make it a little more user friendly.