The conception is kinda simple. Every player would have a desert agle and 1 hp so you would only have to shot once to kill each enemy. Obviously the last alive player would win the round. I don't feel it neccessary to explain anything else since it's not a complicated idea, but it could be fun maybe. However I drop a video below as an example:
https://www.youtube.com/watch?v=DjKqj50CRFU