Tap where you want to shoot.
There aren't many games where you could write a full review on Twitter, and still have enough characters left over to provide a link to an amusing YouTube video of a strange pair of dancing tennis balls. But Ego City Invasion is one of them, and in many respects that's a credit to the immediacy and simplicity of its gameplay.
You may have heard of Ego City if you're a social PC gamer, and this is indeed the same virtual city mentioned in the title. The premise, apparently, is that Ego City is under attack, and it's up to you to repel the invading orc army single handed.