This is one of the more unique concepts I’ve encountered. As a person who doesn’t really understand minesweeper, I was still able to pick up on the basics by playing this game. Honestly, my favorite part was picking up the gun and using it to shoot at the tile. It was a fun and creative way of picking a murderer, rather than just pressing a button.
My suggestion would be to go further with the minesweeper concept. So maybe on a harder difficulty, there are not just murderers but hitmen who are tasked with eliminating the player. They would be like bombs from minesweeper.
Great work!