Colonization: Crumbling Walls

As he paced about the wall, Tarian stopped when he came to a devastated section. He ran his fingers along the shorn stone and glanced at the boulder, now entrenched in the ground just behind the wall. Thankfully, the defenders stationed there evaded the massive rock hurtling past them, saved only by a defender's shout. Tarian shook his head and turned back to the swelling ranks of monsters...