If some players enjoy current version of survival mode, you might consider adding a new mode, hardcore one. The base of this mode consists in rare and balanced loot. That's very important. Loot - Loot has to be at that point where players have to scavange hard to find a weapon, scavange harder to find a better weapon and so on. Apart from weapons, all the loot has to be rare. Just add possible loot spawns to all buildings players can enter, cause I've seen a lot of empty buil