I've played through about 10 characters now, all but one of which I was unable to get a good start with because zombies seem to chase forever. While this is not necessarily a bad thing, it becomes so when you disappear around three corners, lie down in a location a block away out of eyesight and they chase after and find you despite no noise being made and you not being seen. This is particularly a problem given that it is almost impossible to kill a zombie without being damaged in the process, particularly hordes of them.