Bulldozers

Bulldozers:

Some stages have pre-designated Bulldozers situated in the map. When activated, they run back and forth a fixed route – reaping through anything that moves within its path. They offer a ton of help trimming down the size of the attacking wave for cheap. They are also not attacked by the Zombies so they are quite reliable and should last all throughout the level.

Bulldozer

(Passive upgrade to learn using Bulldozers on field)

Start up the bulldozer. In some locations, you will come across these 50-ton construction vehicles. Abandoned after the Outbreak, a skilled mechanic can easily transform these machines to powerful zombie sweepers. Once they are started up, they will keep rolling and crush every walking corpse that wanders in their path.

Bulldozer -25%

(Bulldozer passive upgrade)

The cost of starting up every bulldozer will drop by 25%. Additionally, the machines will move faster by 15%.

Bulldozer -50%

(Bulldozer passive upgrade)

The cost of starting up every bulldozer will drop by 50%. Additionally, the machines will move faster by 30%.