By like Dead Rising I meant by trying to survive until a set amount of time has elapsed.
If it is indeed magical zombies I say no player-character should have magic powers. Rather there should be magical devices of some sort scattered throughout the map the the players need to destroy. When each is destroyed the dead in it's area will no longer animate but existing zombies will continue to function unless all devices are destroyed.
That's how I would do it any way. It would give the players something to do in terms of locating and destroying the devices. There could also be some sort of guardian at each device as a "boss fight". This is just a suggestion but that's how I would do a magical zombie rp.
If it is science zombie it could be the case that the government sprayed the area with a chemical(vaccine) that will kill(stop) all the zombies but it is very slow acting so the players need to survive until it takes effect. Of course things do not have to go that smoothly, Resident Evil players know that fighting bio-hazards with chemical agents don't always go well.
