A good strategy is to buy as many salvage yards as possible, ( they get you more money ) and when the zombies get too close to your base deploy some shovel men.
Max out the number of salvage yards you can get because they are the key to winning. Whenever you feel that the zombies get too close to you trailer immediately deploy some shovel men.
Once you have maxed out your amount of salvage yards, make some trailers until you can't make anymore. Remember to keep deploying a couple of shovel men ever once in a while to stem the flow of the zombies.
This picture shows a later stage in the game where the yee-haw powers show up. the yee-haw powers are the three icons above the salvage yard that are just super powers. To activate them you must have enough yee-haw points which are the points right next to the amount of cash you have. To use a yee-haw superpower, simply tap one of the yee-haw icons. I recommend to use the 4000 yee-haw point icon whenever you have enough yee-haw points. You should use yee-haw powers often to end the round quickly because the zombies get harder and harder as the round goes on.
The other icons besides the salvage yard, trailer, and yee-haw powers, are icons that enable you to use much much stronger units than shovel men including:
The Angry Farmer, he shoots from a range.
The Survivalist, a car that has a mounted machine gun on it.
The Moonshine Bomber, a man that throws long-range bombs made of moonshine alcohol.
And finally, the Preacher, the best unit in the entire game, he makes enemies turn against their own men, in a sticky situation, say the enemy sends a very strong unit at you, deploy one of these and the enemies unit will be yours.
