What i would want in this Add-On:
*Have to buy guns with points
*Get points for killing a zombie
*Use points to open doors
*And a random weapon box
*Only 2 people play at a time
*Levels, like each gets harder and harder
*Get different amount of points for shooting zombies with different guns
*Can only hold 2 weps
*Zombies can only rip down pallets then climb into the house
*Can repair pallets and get points for them
I already have the building of it covered.