One player starts as a zombie, hitting another player infects them. Zombies win by turning everyone into zombies, players win by surviving for the duration of the round.
1 thing to figure out is how to determine who wins and how much they win. If zombies win, does only the first zombie win or do all zombies (effectively everyone but the final survivor) win? If all zombies win, do they all win the same amount? Or do their rewards scale based on how long they've been a zombie and how much they did as a zombie?
One player starts as a zombie, hitting another player infects them. Zombies win by turning everyone into zombies, players win by surviving for the duration of the round.