1) Invest in your future.The temptation to quickly start upgrading your guns, radar, and other whiz-bang improvements is strong, we know, but try to resist, at least at first. In the “Extra Upgrades” menu is the Zombie Bounty upgrade. Spending coins there increases the amount of money you get per zombie kill. Dumping some coins into this upgrade right from the start will mean more coins earned in the future. Patience pays off.
2) Beware damage radius improvements Guns can be upgraded in four ways: reload speed, damage radius, rate of fire, and bullet velocity. They all sound pretty great, right? But the damage radius (larger spread) upgrade actually has an unintended consequence. Remember you’re only supposed to be killing zombies - civilian deaths will result in a game over. And a larger damage spread makes it that much easier to accidentally off a human. This upgrade can be nabbed eventually, but we wouldn’t make it a top priority.
3) Civilians: who needs ‘em? Every civilian that successfully makes it to the bunker earns players a decent number of coins. However, they’re really more trouble than they’re worth – especially with the aforementioned Zombie Bounty upgrade. Remember, kill three civilians and its game over. When you see zombies attacking a civilian, don’t intervene. For one, the pinpoint accuracy needed to take out the single Zed will eat up a lot of valuable zombie killing time. And with the civilian gone, you won’t need to worry about where you’re firing.
4) The right gun for the right job With point three in mind, if you’re the type of player that just has to see civilians survive, make good use of the fast and accurate 25mm. Using any of the bigger guns near a civilian greatly increases the chances that your fire will land a little too close, accidentally killing them. The massive 105mm is obviously best for large, concentrated groups of zombies. Finally, the 40mm should be where you spend most of your time – it’s a great combination of speed, accuracy, and zombie-killing power.
5) Use the big gun! The huge 105mm is there to be used! The temptation is to “save” it for moments of extreme zombie slaughter is tempting, but its reload time isn’t that long. Players should use it every chance they get, even if it’s just to take out a smaller group of undead. One nice rhythm to get into is to switch to the 105mm and fire it off while waiting for the 40mm to reload.
6) Beware the big zombies At around roughly 300 zombie kills, the larger hulking monsters start to appear. They must be dealt with immediately. Remember, if only one zombie reaches the bunker, its game over. So don’t wait for the proximity warning to go off to begin taking them out. Obviously the 105mm is recommended, although multiple 40mm rounds will work in a pinch.