I didnt care so much for the movie.
When they up and decide to leave the mall. It just wasn't believable...like "We've got a good thing going here and could last a long time. We've got food, a safe place to sleep, plenty of entertainment. Hey I know! Lets make a dangerous run to a dock where a boat may or may not be to set sail for an undetermined location that has a strong chance of being just as infested with zombies as our current location! No guarantees of food or safe shelter!" And then everyone, even the skeptical asshole that hates everyone, agrees to go along with it.