SAS: Zombie Assault 4

Game Description
Clear the Undead! Awesome upgradeable guns and armor, unique class skills, and 4-player co-op! Play the most intense zombie shooter on mobile, from the makers of Bloons TD5.

A viral outbreak on a distant Trans-Federation planet has unleashed the horrors of humanity's past. Powerful, fast-growing zombie hordes threaten humanity's survival, and the only ones who can fight back are the skilled, well-armed SAS special forces.

Choose from 3 character classes, maximize a fully customizable skill tree, and select from hundreds of weapons and armor to create the ultimate zombie-killing hero.

Play dynamic, challenging levels in single player or 4-player co-op multiplayer, leaving our ravaged civilization with the last best hope.

Intense Action Zombies swarm in and explode to pieces under your hail of bullets.

Each of the 17 unique zombie types has special attacks and behaviors, and they can evolve - revealing terrifying new powers as you progress through the game.
Just when you thought you had defeated them all, savage zombie bosses hunt you down, spitting out acidic worms or lashing out in rage mode.
Lead the action across 7 story-driven maps with different victory conditions, learn their strengths and weaknesses.