The hand-drawn sketch style is very nice and stood out a lot! Well done! I also like the mafia cookies design, seems like you've put a lot of effort into that! The gameplay is also enjoyable, a bit on the easy side for sure, especially if you get better weapons than your starting pistol (and god forbid if you accidentally took the shotgun). I made it to the end of the level, and sadly, the boss clipped out of the level and I was never able to kill him.. sad
For some criticism, I think the main thing is that the audio, especially the gun sound, is a bit too loud. It drowned the background music and forces me to tune the volume way down to make it bearable. Another thing is that it would be nice to know what the reloading progress is, so less guesswork on the player to know when it will be ready to fire again.
Anyway, I think you did quite a good job! Keep up the good work!