[8] After winning a battle, the player gains rewards including new weapons and parts for their trench, and decorative hats similar to Team Fortress 2.

Two war veterans, Frank Woodruff and Vladimir Farnsworth, survive the attack and gain super-intelligence and a knowledge of advanced technology.

Frank, having previously lost his legs in the war, uses his knowledge to design and build mechanical walking platforms called "mobile trenches," giving other disabled soldiers the ability to move again.

Vladimir is driven insane by his own invention; bent on global conquest, he constructs Monovision-based robotic creatures, derogatorily called "Tubes", designed to spread the broadcast and lays Monovision cables across the world.

To bolster morale, Tim Schafer divided the team into four groups, challenging to develop a game prototype within two weeks for review by the rest of the company.

When Brutal Legend was completed and Double Fine was told to discontinue work on a sequel, Schafer turned to these four games and sought publishers for them as smaller, downloadable titles.

[11] The game's art style is inspired by men's magazines of the 1940s and '50s, which illustrated "the sense of adventure, bravery, camaraderie, drinking, and good old-fashioned face-punching violence," according to project lead Brad Muir.

[16] Ultimately, at the Gamescom 2011 conference, Microsoft announced that Trenched would be retitled as Iron Brigade in Europe, with a release set for November 2011.

[6] The renamed version and European release were originally scheduled for September 2011, but Muir explained that much of the changes had to proceed through various divisions of the Xbox Live Arcade game certification process, delaying the updates until November.

[5] The first downloadable content for the game, Rise of the Martian Bear, was released on February 1, 2012, and introduces a new campaign, more items and survival mode maps.

Anthony Gallegos called it the best downloadable title he's played all year long, stating that its combination of skillful writing, fun shooting, and tactical tower defense makes for hours of replayable gameplay.

GameSpot gave it an 8 out of 10 rating, praising the combination of tower defense and action gameplay, varied missions with replay value, fun solo and co-op modes, and customization but criticizing the chore of collecting scrap.

1up gave it a B rating, criticizing that the game doesn't include a local co-op option but stating that if you have a friend to play with, it can be a blast.