Players of zombie typocalypse will have the task of defending the tunnel and clearing it, because zombies are getting stronger and they may have the chance of capturing whole jet. So as you guess you will have to kill as many as you are able to do with our weapons. If you want to kill tens of them easily then you should upgrade the guns. Maps are changing after completing the levels, do not forget that zombies can run after your direction, so do not let them go nearby . Use the automated guns which will make the process much easier and funnier for you to enjoy.