Very stylish, fun, and quite challenging. Santa with a gun is the most dangerous enemy; he shoots very accurately, quickly, and deals a lot of damage. And if there are several of them at once, they can one-shot the player. Fortunately, the levels are full of cover, and there's excellent dynamite, which solves this problem.
I was only a little disappointed with the boss fight. It has very little tactics and a lot of chaos. Basically, the most effective strategy is to shoot from the doorway.
It would probably be better to have the player enter the boss arena from above, preventing them from retreating back to the door. And scatter gifts with dynamite around the arena. And maybe add a little more cover.
But overall, your game is great. I had a lot of fun.