Zombie Infection is an action horror game with some adventure elements, viewed from a top-down perspective. At the start of the game the player takes control of Anderson, the leader of the team. When encountering an enemy Anderson automatically draws his gun and a vertically moving crosshair appears in front of the enemy. The player needs to time the shots to do as much damage as possible. A well aimed headshot is enough to take down any zombie. At the start of the game the player has a simple handgun, but at checkpoints he can buy new and more powerful weapons of all different kinds. There are also other items that can be bought, such as health packs and energy drinks. The player pays with points that he earns for taking down enemies. In addition to killing things the player can interact with different people and objects. Some objects can be grabbed, pushed or kicked away. The player can also pick up items that can be combined to create new ones.
Later in the game the player also gets to take control of the other two members of the team, Mike and Shawna. For each character the play style is different. While Anderson is trained in using guns and heavy weapons, Mike prefers melee combat. Early on in the game he finds a katana but he can also do ranged combat with shurikens. Shawna is the journalist of the team and always carries a camera with her. Playing as Shawna is therefore less combat-oriented and more about stealth. With her camera she can tape things she sees and then sell it as exclusives. She can also use a lock pick to get access to otherwise locked down areas. Some monsters need darkness to be protected and these can only be taken down after being weakened by the light of Shawna's camera.