Saw a playthrough of it just last night. It's a hack and slash game where you play as the slasher, and you kill people during the winter holidays (Xmas and New Year). If one of your victims manages to leave the level (house, store, etc.), you lose, so you gotta move quickly and there's a bit of strategy involved. As you progress through the game, you unlock outfits (default is a Santa costume) and weapons (default is a kitchen knife). It's not really clear why you become a slasher (the very first level is your boarding school, and you're punished for bad behaviour, maybe that's the reason?), but once you've grown up, a living Xmas tree orders you to kill "for great justice" or something. The ending was a hilarious whammy. I wonder if there's gonna be a sequel.
Gave it 4/5 because it's a bit primitive, and I'm not a fan of the subject matter. I liked the fact that you get to unlock costumes and weapons, and the talking xmas tree telling you to kill is funny (if not a bit too realistic, given how deranged slashers tend to be).