If zombies is strong, can I still kill them?

When you click on a zombie, you can see the required power level needed to defeat them. You ALWAYS have to be higher in order to battle and win against them.

You can do this a few ways:

1. Level up your barracks so you can deploy more troops in your APC.

2. Level up your shooter, fighter, and vehicle buildings to make higher ranked soldiers.

3. Research via institute power up's to help soldiers become stronger.

Also, with the new update, unless you are a certain level it will not let you attack that Zombie without you reconfirming you'd rather waste your troops instead of recalling them.