As you go through each level, remove alien plants and aid fellow humans. It is your responsibility to make aliens more friendly. You are responsible for space trooper enrollment and weapon upgrades. Save all hostages from alien plant invasions and shoot aliens when you aren't looking. Some of these plants are explosive. Explosive bomb plants can be used as a way to kill aliens and locate valuable minerals. Be careful, as the explosive could cause serious injury. As you advance, you'll be able earn more money to buy better troops. You can use your laser gun for building troops that can be upgraded to defeat all alien forces. You must eliminate all hostiles, and rescue all civilians. You think you are capable of accomplishing this feat?
How To Play City Siege 4. Alien Siege