WOW!! I love everything about this game.
It's very simple, straight to the point, but the loop is so engaging I had a ton of fun and will be playing more to chase high scores. My first playthrough got a score of 165 (if you don't count my first where i died at 2 because i didn't figure out the gun).
The atmosphere provided by the dark graphics and crunchy audio is very forboding. As the game sped up it became a hectic test of quick reaction, but the door being there kept me feeling like I had some control over the situation.
When the door unexpectedly broke with no way to repair, that point forwards was the peak for me. I stopped feeling like I had any control over the situation, but in the best way possible, like it was a true test of everything I learned up to that point. It felt crazy having 5 monsters come at me with no door in a row. Since you can leave candy on the floor, I locked in to a routine of spam dropping candy on the floor where i left the gun right beneath the bowl to auto-reload. It felt very flow-state. I only lost when I accidentally domed a child with high-velocity sugar.
If I could give any criticism, I would say implement some new kinds of monster and trick-or-treaters so it's not as black or white what i'm about to deal with (the fake-out approaches made things more interesting, for example).
I hope you're able to turn this into a full-fledged game, if you ever plan on it!