Hey, the credits button doesn't work if you come back to the first screen after playing :'( It's the more rewarding thing for a game developper, so try to fix it, please =)
I found a very helpful glich : when you have to search and you have enough supplies to travel, open the map and close it. Then search in your current city and start the night. In the next day, after searching and viewing the results, close the story book and you will have the possibility to search for supplies and survivors a second time.