Galaxy Campaign app for iPhone and iPad

Aliens are plotting to invade Earth and enslave human beings. Now we need to save earth and entire human beings,fight against aliens as a warplane pilot. Aliens have many machines which features different power. Some with powerful machine guns,some come close to earth invisible as a ghost,some with really fast speed,some disguise themselves as something else,BE CAREFUL of those creatures and machines!

GAME RULES
At the beginning,you can only fire at aliens one after another. As you level up,once you get machine guns,you could fire continuously. When bullets are used up,they will be automatically loaded,but you have to wait for a while before that. Fire at different stuff for bonus,some will really SURPRISE you! Tap to fire, THATS IT!