Truly, double pistols are useless compared to when you get double shotty. First get dog to help, then grab shotty, then save for couble shotty, then get better dog, then save long time for minigun. Best way to get kills is to run from car to car and try to break them. You are looking for chainsaw because with it its one hit kill on any zombie and you are invincible for duration. Once chainsaw runs out, repeat.
Personally, I liked the 3rd in this series better, because you were not as restricted on what element of your units you were allowed to use. now you are restricted by what type your hero's are. I, for isntance, am having trouble finding a cold "hero" to use. Thus, I can't get througha a certain part of the storyline in which its virtually impossible to do without. You are also restricted to two unit types per hero, rather than in the 3rd, you chose what your unit would be along the way. Don't get me wrong, this is a great game, I just think that you are too restricted by what type of hero's you have.
yeah, i found the same thing Redz, I was just sitting there waiting for anything to get close enough to hit me, but nada, sat in the same spot for the whole last boss sequence as the midget ship...