A unique combination of top-down shooter and tower defense strategy. You are an invader! Use weapons or lure the enemy into a deadly labyrinth of defense towers. Plan your attack in Build Mode by building a variety of towers, or jump right into the thick of the fight. Build defensive towers and defeat enemies that attack you on maps that give you incredible planning freedom. Destroy buildings and bridges to strengthen your defenses or just for fun. For the first time in the tower defense genre, become the owner of an arsenal of unique alien weapons and apply defense strategies never seen before.