Mostly a well executed game! Letting the player build their first snowman without any threats is a great way to let the player learn the mechanics comfortably before throwing them into the deep end.
The lack of BGM actually adds to the horror vibe of the game.
My only point of critique is there's not much indication whether dropping an item will cause it to get stacked/activated as opposed to just plopped down somewhere. This is a problem when you're trying to stack snowballs and putting a snowball down instead drops it on your location, nearly pushing you into the hat.
Some better indication on whether snowballs are stacked would also be good, I spent some time not realizing that a given snowball was already stacked and not behind the rest of the two.