Part 2, Once you have a decent defence and around 30 or 40 people you want to start researching. Make sure you capture more than one research facility and tons of apartments, suburbs and junk for the people(this is part of part 1 sorry). If you get useless survivors at the 25+ people mark make them into scientists and research all the abilities, but do not get electricity until you have reclaimed city hall. Once you have the happiness at 50% from all the churches and bars you get(at least 4) get 5 leaders and start rebuilding the government at city hall. This is when you put everyone in the fort and do nothing for 10 turns while you face hordes every 2 turns. Thats when all the malls, police stations, and soldiers come in handy. I had about 600+ defence and got over ran once. Its ok to get over ran once or twice since it lowers there attack too. I wish you luck using my method
If you want the hard badge this is the method I used to get it Part 1. First thing is get nothing, but soldiers and survivors they are the most important key in winning and also get a school immediately and transfer all the useless people into soldiers. Second capture all farms and scavange everyday to keep your food supply up and attack in large groups, I had 5 survivors attack a 30% danger place and we ended up kill all the zombies. Third make sure you get at least 6 builders to mass spam reclaim once you send your soldiers. Fourth make sure you get your hands on as many police stations and malls and build defenses for all the malls, I had 1 guy guarding my place with 185 defence. You don't have to research, but it comes in handy. Fifth make sure you store all you people in the defence before a raid. Basically to win with little and or no research find the town hall reclaim it, get 50 happiness and 5 leaders and survive 10 turns.
 "Rebuild"){kind=icon}
 "ELEPHANT RAVE"){kind=icon}
 "Tyrant"){kind=icon}
 "Man in Gap"){kind=icon}
 "Junk Wars"){kind=icon}
 "Ministry of War"){kind=icon}
 "Zening"){kind=icon}
 "TDP3: Ultra Kill"){kind=icon}