Iron Brigade is a downloadable video game developed by Double Fine Productions and published by Microsoft Game Studios for Xbox Live Arcade. The gameplay of Iron Brigade combines elements of the tower defense and third person shooter genres to create a hybrid game. The game occurs in an alternate reality in the first half of the 20th century, following the Mobile Trench Brigade in its campaigns to reclaim the world from the robotic Monovision menace. The game was released on Xbox Live on June 22, 2011, and can be purchased for 1200 Microsoft Points.
During the Great War, American soldier Frank Woodruff loses his legs in combat and is reassigned to a communications monitoring post in the Pacific with Vladimir Farnsworth. As Woodruff and Farnsworth listen to enemy radio broadcasts, a mysterious signal later dubbed the "Broadcast" sweeps across the world and causes the brains of thousands of people to explode. Woodruff and Farnsworth become the sole survivors of the Broadcast and somehow gain a vast technological insight. Woodruff uses his ability to design and build mechanical walking platforms, allowing other disabled war veterans to move freely again. Farnsworth, however, creates a device that obviates the need to walk: the Monovision. With the Monovision, people could experience the world from the safety of their own beds, there would be no need to venture outdoors.
Madness soon overcomes Farnsworth. Bent on sharing the "wisdom of the Broadcast" with the world, Farnsworth constructs various Monovision-based creatures, derogatorily referred to as "Tubes", to serve as his army and spread Monovision cables and conduits everywhere. Woodruff weaponizes his walking platforms into "Mobile Trenches" and establishes the Mobile Trench Brigade in 1926 to fend off the Monovision threat. Based on the U.S.S. McKinley, the Mobile Trench Brigade takes the fight to the Tubes in Europe, Africa, and the Pacific.
Iron Brigade begins as Commander Woodruff trains the Mobile Trench Brigade's newest Pilot at the European beachhead. The Brigade fights its way across strategic points in Europe, seeking the source of the Broadcast. Eventually, the Brigade arrives as what is believed to be the heart of the Broadcast and lynchpin of Farnsworth's Monovision army, the Northern Pylon. Initially appearing as a dense cluster of Monovision machinery and radio towers, the Pylon is actually a powerful Monovision creature. The Pylon is destroyed after an intense assault, and the Brigade celebrates its victory over the Monovision.
The Brigade quickly realizes that the Monovision threat remains; the Northern Pylon is only one part of the Broadcast's distribution system. An immense cable stretches southward from the Pylon to Africa. Their mission unfinished, the Brigade follows the cable to find the true source.