Zombie Killer – Overkill Protocol is a paid expansion for the free-to-play base game Zombie Killer. This content requires the base game Zombie Killer on Steam in order to play.

Travel beyond Zombie Island with new battlegrounds, new ways to move, and a powerful ally watching your back.

Fight through three extra levels: neon-soaked Tokyo streets, foggy hill roads in northern India, and the dense neighborhoods of Brazil, each with its own atmosphere and combat flow.

Jump into the new vehicle system and drive on Indian roads, weaving through abandoned cars and smashing through zombie hordes to rack up kills faster than ever.

Unlock a new companion: a cute combat robot that automatically targets and kills zombies around you, giving cover fire while you reload, reposition, or focus on objectives.

Keep pushing your high score and survival time as you combine vehicles, weapons, and your robotic partner to dominate the Hall of Fame.