If a contaminated area exists, you should concentrate on removing it. This is because if the contaminated area remains, regardless of the mission type, the mission can not be completed. If you kill a zombie or deploy a soldier from a cube with a contaminated area and close that cube, the contaminated area will remove. Cubes that do not have contaminated areas should be avoided as much as possible to complete the mission.
When zombies are found, the troop immediately launches attack. The order of appearance and distance do not matter. ① Seek out zombie + ② Deploy troop = Attack zombie ① Deploy troop + ② Seek out zombie = Attack zombie ① Seek out zombie 1 + ② Seek out zombie 2... + Deploy troop = Kill streak You can perform kill streaks by seeking out multiple zombies before deploying a troop. However, the streak will cease if there is a tough zombie. ① Deploy troop 1 + ② Deploy troop 2 + ③ Seek out zombie = Co-op attack Deploying multiple troops before seeking out a zombie will unleash co-op attack. This is useful when killing much tougher zombies.
The numbers showing on the cubes represent the number of zombies surrounding that cube. There may be up to six zombies surrounding a cube. Try and deduce the location of a zombie by inferring from all adjacent cubes. The number displayed on a cube changes when zombies are found. When zombies are found, the troop immediately launches attack. Cubes with red numbers indicate there are tough zombies surrounding the cube.
Seeking out 8 or more zombies and deploying a troop will trigger a helicopter air strike. Chain Gun (x2 attack force) If 8 to 13 zombies were found, a chain gun initiates an attack. Missile Attack (x3 attack force) If 14 or more zombies are seeked out first, a missile launch attack is initiated. Since this is an effective strategy when attacking tougher zombies with high defensive powers, seek out as many zombies as you can before deploying a troop.
Different types of USTF troops and zombies have varying levels attack and defensive powers respectively. Cubes with red numbers indicate there are tough zombies surrounding the cube. Attacking tough zombies with troops with a lower attack power will not kill them and will infect the troop. A more strategic attack is required when attacking tougher zombies with a high level of defensive power. Co-op Attack Deploy multiple troops first and then seek out a tough zombie to perform a co-op attack. This will deal aggrgate damage of all the deployed troops. Helipcopter Attack Attacking after deploying 8 or more troops will unleash helipcopter attack. Troops with a higher power Attack Attack with troops with a higher attack power than the zombie's defensive power.
Touching a deployed troop will cancel, and the icon of the unit will appear on the cube. If you cancel the deployment, you can redeploy the unit at the desired time. Canceling a troop will use up a turn. However, when you deploy again, the turn is not consumed. This is a versatile feature, as units with strong attack power and mission clearing can be used at optimal timing. The number indicating surrounding zombies will remain after cancelling a deployed troop. You can use this information to your advantage such as seeking our further zombies for a kill streak.