GTA: Frontline Defense 2
They say war is for the victors since they conquer more lands. And for that reason, no country would want to lose. Word has it that the enemies are advancing. Fortunately the general has come back from his long trip and is ready to protect the country. The game is played with a mouse and you need to erect towers, where you believe it is more effective. each kill would earn you money, which you can use to upgrade the existing tower or buy another tower to increase the defense. Enemies will come in wave and you need to eradicate each wave before they can get to the base.