360 Junkies writes: "'We need more cannons on the right side!' 'Wait that exposes our left rear!' 'Quick put a turret on the back wall!'. How many times have you heard these phrases? Unless you're a castle designer or having one hell of a snowball fight, these are not normal exclamations made in typical conversation. However, when playing games of the growing Tower Defense genre, it's OK to make these statements. I can't promise that people won't look at you a little odd but at least you can give a good reason for the yelling.
Defense Grid takes place in a futuristic environment. The main objective is that Aliens have started an invasion. To make matters worse they have come to harvest what power is left on our planet in the form of cores that are located around a central point on the map. Players will encounter multiple types of enemies along the way from flying to enemies that spawn more while walking. If the cores are taken, 24 in total, then the level is over and your computer friend, whom is met at the beginning of the game, shuts down..."