Town taken over by crazy ghouls - (inspired by Zombie attack

)
use map of some city (Hub or Junktown for example, which has cool atmosphere for this)
spawn there big amount of ghouls - with high unarmed or using some basic weapons (hammers, knives) with high melee and having some bigger hp or DR (so they wont die easily)
make two team of players:
1) survivors (like 10 people max.) - they will have just some .223 pistols, hunting rifles or combat shotguns and combat leather jackets or leather armours and very few ammo...
2) rescue team (more people) - having Combat Armors and Assault Rifles or M60s or flamers
Rescue team will begin at the entrance to the town and has to rescue survivors (as most as possible) by taking them to the entrance and then defend it against zombies for some time period... survivors will be spawned randomly in the town (just far from entrance) and have to try their luck alone or team up and try to survive as long as the rescue team will help them to go through the whole town to the entrance...
no drugs, rescue team can have paramedic bags...