The fourth game in the series. This game simplifies the options somewhat in that there are three modes to choose from: Campaign, Survival and Armageddon. Within Survival and Armageddon you can select the terrain type you will be fighting on. There is only one type of weapon in this game. You have a mobile unit, with a certain amount of shield power which fires a projectile at enemy units. Do not leave the play area, or die or you will lose.