Total City Defense is a zombie themed survival game where you must complete each level to progress.

Using the mouse and keyboard you control various units, including Troops, Turrets and Drones to make your way through each level rescuing civilians, VIPS and destroying enemy strong holds. Each unit has it's own pros and cons so decision making will win or lose the level. 

Troops are the main unit but can be infected and turn against you.
Turrets are strong but slow and cost more in resources
Drones are fast but have limited fuel and can only be used in combat once.

The enemy will only attack when your troops are in line of sight, so choose your path wisely.

Each level will contain enemy spawn points in which the enemy can grow in strength.

Rescuing civilians and finding dropped tech will let you create more units to help you in your missions.