This game needs a lot of work. It can be a lot better than what it currently is.
The background should be changed to something more fantasy themed instead of a scrolling of a city street over and over again. Could have changed it to a mountain like area as I think that would make more sense for a background here even if it is meant to be a Christmas game in a way.
The game play was not challenging at all. Enemies die upon you touching them which does not make that much sense. Health can be easily regenerated too. Lastly, the bosses are far too easy to defeat, they go down in around ten hits each. Bosses could be moving faster and firing more than they actually. Could also fix it so allies don't fly by during battles to keep it challenging along with upping the amount of health that they have.
The music, while not that bad could have been more diverse. The normal music, then the mini-boss songs would have been the same, lastly, Santa could have had a unique boss theme instead of the music never changing at all throughout the game.
The sounds used were nice I suppose, the explosion being someone making an explosion sound with there mouth is cool.
Overall, this game could have been much better than it was. However, it does show you are improving yourself a bit with how you make games compared to your games when you first began here. Best of luck with future games.