What is this game called?

You have to defend a fort from people trying to destroy it. You can hire gun men, missile silos, workers, walls and stuff like that. You can upgrade your weapons and such depending on how many attackers you kill. This is a online fllash game and its fun as hell. You also have 40 days to defend it. After the 40 days are up, you get a new weapons called the Irish Fist i believe where a fist comes down and crushes all the attackers. You can also but ammo and diferent size clips. Anyone know the name??