The game features the character of Eddie Riggs (voiced by and modeled after Jack Black), a roadie who is transported to a fantasy world inspired by the artwork of heavy metal album covers.

Brütal Legend was generally well received by game reviewers, praising Schafer's vision and writing of the heavy metal-inspired world, and the performances of the voice cast, particularly Black and Osbourne.

Doviculus is assisted by his glam metal human minion, General Lionwhyte (voiced by Rob Halford and based on David Bowie with the name being an allusion to glammetal band White Lion) whose hair is so big "and luscious" that he uses it to fly, flapping it like a pair of broad wings.

[15] During a gig for Kabbage Boy, Eddie is crushed by falling scenery while trying to save a member of the band; his blood lands on his belt buckle, in reality an amulet for Ormagöden.

They discover writings left by the Titans that Eddie is able to comprehend, and build a hot-rod, the "Deuce", that they use to escape the Temple (confronting a giant lamprey-like monster) and travel to Bladehenge, the base for the small human resistance force led by Lars and Lita.

As they travel through exotic lands and find more allies out of the pyromanical Fire Barons and the amazonian Zaulia tribe, they come across evidence of Eddie's father, the hero known as Riggnarok in this time.

It tells that Riggnarok traveled to the future to attempt to learn the secrets of the Titans to bring back to the past in the humans' ongoing fight against the demons, but never returned.

[17] Part of the game's inspiration came from the fantasy worlds that the lyrics and album covers of metal bands implied but rarely made it to music videos, thus allowing Brütal Legend to "fulfill the promise" of such lore.

[20] Schafer had previously explored the idea of a roadie sent back in time with the character of Hoagie from Day of the Tentacle, but Brütal Legend represented an opportunity to expand on it further.

[24] The metal/motorcyclist lifestyles and Norse mythology also inspired the game's open-world environments, such as amps carved into the face of a mountain, a forest where tires replace leaves, giant axes and swords piercing the ground, spandex covered temples, and mining facilities where human slaves excavated car and motorcycle parts.

[32] Lemmy was brought on board to play The Kill Master after Schafer and his team had developed the character's role in the story who assists Eddie by healing his allies through a giant bass harp on the back of a chopper.

[32] Curry considered the role "perfect" for him when Schafer described Doviculus to him as "big and tough, but also has this kinky side who, when hit with an ax, might scream in pain or squeal with delight".

[41] Richard Horvitz, who voiced protagonist Raz in Schafer's previous game, Psychonauts, cameos as the lead guitarist of Kabbage Boy and as a car-lift operator that assigns Eddie certain side missions.

Further voice acting work has been provided by veteran video game actors such as Zach Hanks, Kath Soucie, Dino Andrade and Jennifer Hale.

[33] Having completed the multiplayer stage battle portion of the game first, Double Fine found it easy to gradually introduce the player to its more advanced aspects during the single-player campaign.

Within the span of a few months the combined asset size tripled, endangering the game's ability to fit on a DVD and causing performance problems throughout the company's development systems.

[46] While Brütal Legend's fate was unclear, Schafer was not able to talk about the project to avoid causing problems with any potential business deals, until EA Partners picked up the game in December 2008.

[32] Instead of a sequel, Double Fine began work on four smaller projects, Costume Quest, Stacking, Iron Brigade (formerly titled Trenched) and Sesame Street: Once Upon a Monster,[55] based on prototypes they had created from "Amnesia Fortnights" during the development period where they had lacked a publisher.

In these two-weeks sessions, the Double Fine team was split into four groups and each tasked with creating a small prototype game to share with the rest of the company; all four mini-games were well received internally.

[65] In July 2009, Double Fine issued a countersuit against Activision, citing that the latter company had abandoned the project before, and was trying to harm Brütal Legend during its critical marketing phase, as well as trying to protect its Guitar Hero franchise.

[70][71] Though most of the developers involved in the game were shielded from the effects of the lawsuit, Double Fine's Caroline Esmurdoc noted that it took a significant toll on Schafer and the other lead executives at the company.

[76] At the 2009 Download Festival in Donington Park in England, Electronic Arts arranged for 440 fans of Brütal Legend to help to break the Guinness World Record for the largest number of air guitar players, all simultaneously playing to "Ace of Spades" by Motörhead.

[79] A promotional concert for the game was held at the 2009 Comic-Con International Convention in July 2009, and featured the metal artists Gwar, 3 Inches of Blood, Unholy Pink, and Keith Morris.

[83] A demo version of the game was made available on the Xbox 360 Marketplace and PlayStation Network Store; it was available for a limited time on September 17, 2009 for North American users who had pre-ordered the product through GameStop.

[21] Schafer had identified many of the more well-known songs on the list, while Ridgway was able to locate mission-appropriate, more obscure titles for inclusion; for example, one mission, given by the Killmaster (voiced by Lemmy Kilmister), involves rescuing female troops for Ironheade's army; Ridgway had been able to locate a cover of "Bomber", originally recorded by Motörhead (Kilmister's band) and performed by the all-female metal band Girlschool, recorded in their 1981 split EP St. Valentine's Day Massacre.

[7] Schafer helped to select three songs—"We Are The Road Crew" by Motörhead, "The Metal" by Tenacious D, and "More Than Meets The Eye" by Testament—to appear in a pack of Rock Band downloadable songs that was made available the same day as Brütal Legend's release.

[100] Davis believed that the juxtaposition of all the elements that made up the heavy metal fantasy world were the game's greatest strength, often being "both giddily ridiculous and fist-pumpingly badass" at the same time.

[101][104] Some also considered the single-player campaign Stage Battles to be too easy, winnable by brute force,[99] and that more advanced tactics would only become apparent as one played in multiplayer games, including learning the abilities and advantages of the other units of the factions other than Ironheade.

[97] In retrospect, Schafer lamented that they did not include enough tutorials in the game to guide the player as to "naturally how to play the strategy part a bit better", as they had come to accept over the years of development, and tried to use the Double Fine blog to explain some of these aspects.

[99][100] The lack of a mini-map, replaced by either following a glowing light from the sky illuminating the player's target or by navigating based on the Deuce's turn signals, was criticized for making it difficult to explore the game's world.