Zombie Defender is a strategy game where the goal is to keep enemies from reaching the players stronghold. The player does this by strategically placing tower turrets that shoot projectiles at enemy zombies to eliminate them. The player has the option of purchasing different types of towers which each provide a different strategy. Over time the waves of enemies will get stronger, but at the same time the player is rewarded with credits to purchase and upgrade existing towers damage, attack range, and attack speed.