Walls

Description
Can be used to fortify your base. You can keep ground units off attacking your buildings and let your turrets shoot at them if you have good walls. "Defensive structure used for fortification purposes. Blocks the path of ground units."

- In-game description

Tips:
 * Be careful of Kamikazes, they are the wall's worst enemy as they were trained to knock walls down directly on a suicide blast!
 * Moles can dodge walls by going underground.
 * 3D physics are considered with these walls when it comes to blocking attacking units. For example, Bazookas can always shoot over walls if there is a building or a turret behind it. However, when units are very close to walls, they might actually ignore those walls and directly shoot the turret on the building.
 * Low-to-the-ground units, when targeting a structure on the other side of a wall, will shoot straight into the wall first if the wall is high enough.
 * A level 1 wall won't block much, but a level 2 wall will block the fire of Beetle tanks and any other infantry until it is destroyed; Bazookas on the other hand, won't be blocked unless they are right next to the wall, as the Bazooka's missiles reach its maximum height off the ground at around 40% of its range.