ZOMBIE DEFENSE PROTOCOL

Hold back 30 waves of zombies with towers you build yourself. Easy comes with 30 lives and 50% extra rewards, Medium has 20 lives, and Hard gives 15 lives and pays 30% less in rewards. Not every tower hits every threat, and mixing tower types matters.

Ten towers, including Gunner, Sniper, Mortar, Minigun, Laser, Frost, Flamer, Tesla, Recon and Cannon. A $50 Gunner that can hit umbrellas. Recon, a support tower that buffs the towers around it, spots invisible enemies, and gets past shields and umbrellas. Zombies with shields or umbrellas, invisible zombies, and crawlers. Every fifth wave, zombies that arrive by car. Bosses that split into swarms on death, so a kill doesn't quite end the fight.

Choose a difficulty, then press Deploy to start. Pick a tower and click open ground to place it. Click a placed tower to inspect, upgrade or sell it. Call the next wave early, and set the speed anywhere from 1x to 10x.