The art style for the game was based on the work of Frank Frazetta and inspired by heavy metal and rock album covers. The team only considered the addition of elements to the artwork if they felt it would be something that could be seen on such covers. The setting includes hot rod-like engines that grow from the earth like a "V8 Truffle Of Speed", with design inspired by the designs of Ed "Big Daddy" Roth. The art team wanted to avoid creating "another brown-gray game", and strove to use the wide color palettes that are associated with heavy metal art. Cutscenes in the game use the game's engine, though some pre-recorded scenes from the engine have also been prepared with the help of Tasha Harris, a former Pixar employee who helped to animate character's faces during cutscenes.

The game features over 80 unique characters in addition to the main protagonist, Eddie Riggs. Initial designs for Riggs was modeled after Lemmy Kilmister, and though the model was changed, the signature vest, tour pass and cigarette of the character remained part of the character design. As the character continued to develop, they began to add more aspects of Black's character, an "enthusiastic fan" of music, from School of Rock. Ultimately, Riggs' design came to become half Jack Black and half Glenn Danzig. The art team was able to use videos of Black's performances to add additional features to the character, such as "all his crazy eyebrow stuff he does". General Lionwhyte, who has "fabulous hair", and his minions are based on the glam metal fad of the 1980s which displaced heavy metal to the disappointment of Schafer and other development team members, and became the opponents of the game. To help create a more mature game with concepts that could be used to pitch the game, the art team created several factions that represented different parts of the heavy metal experience. Each faction had their own "exaggerated, simplified shapes and strong silhouettes" as to help distinguish each faction while also reducing the development costs. Inspirations for such factions include Nordic imagery, goth metal, and the artwork of Hieronymus Bosch. Additional characters include headbangers, "gravediggers", and "battle nuns". As the game features over two hours of spoken dialog, the art team wants to make the characters' faces and performances stand out, creating "clean, easy-to-read faces". The team had to change from their initial cartoony textures into more detailed ones that stood out on high-definition displays while exaggerating other features of the characters.

The user interface and menus were created by Joe Kowalski, who had previously worked on similar game elements for Guitar Hero, Guitar Hero II, and the Rock Band series. Much of the game's interface elements used a medieval woodcut art style, and were designed to contrast well against the world's graphics. The introductory menu is presented as an interactive movie created from live action clips of Jack Black manipulating a prop gatefold vinyl record album, using Adobe After Effects to provide the on-screen text, controls handling, and stitching of separate scenes into a seamless movie.

Brütal Legend includes over 35,000 lines of spoken dialog, mostly written by Schafer. In addition to Black, Lemmy, Judas Priest's Rob Halford, The Runaways' Lita Ford, and Ozzy Osbourne provide character voices for these lines.

Schafer's original vision for the game had not anticipated a celebrity cast. In particular, though Eddie came to resemble Black, the team had not planned on having Jack Black voice the character. After learning that Black was a fan of Schafer's previous game, Psychonauts, they met with the actor/musician and recognized he was an avid gamer and metal fan and understood all the choices the team made in the game, and subsequently signed on for the voice work. Black also performed live-action sequences as himself used for the in-game menu screens and additional promotional material. Once Black had signed up for the project, Schafer found that other artists and people involved in the heavy metal scene became very interested in participating through a domino effect and word of mouth, allowing Schafer to sign them on as voice talent or as part of the game's soundtrack.

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. The original character, a man with a top hat and beard, was considered out of place by Schafer, leading him to consider famous bass guitar players and quickly recognizing the need to have Lemmy play that role. Halford plays two characters, General Lionwhyte and The Baron. Schafer had selected Lionwhyte to capture Halford's ability to scream, and found his abilities in the studio beyond what they expected. They created The Baron character specifically for Halford, as while Lionwhyte was considered a "heavy metal Stewie [from Family Guy]", that character was the complete opposite of Halford, while The Baron captures both Halford and Judas Priest's attitude. Lita Ford voices Rima, queen of a group of "Amazon-like jungle women"; Schafer considered the similarities between the lack of clothing that Rima was designed with and Ford's outfits from the 1980s, staying true to the development teams' memories of her. Osbourne plays The Guardian of Metal who helps the player upgrade their equipment; Schafer commented that both the character and Osbourne, while dark and brooding, are "really upbeat" and "optimistic".

Though Ronnie James Dio of the band Dio had performed parts for the game, his role was replaced with voice work from Tim Curry. While the change was speculated to be due to tense issues between Osbourne and Dio, Schafer noted that as Dio's intended character, "Doviculus, Emperor of the Tainted Coil", grew, they found that Curry fit the role better for the part, citing Curry's role of the Lord of Darkness in the film Legend as a key factor; Schafer would also later state that Dio's part was cut due to a combination of "really complicated reasons" and other circumstances outside their control. 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".

Similar to their experience with bringing Black onto the project, obtaining the voicework of the metal artists were also unexpected but beneficial. This led to some confusion during voice recording sessions; both Lita Ford and Rob Halford had difficulties with lines involving a character named "Lita Halford". Furthermore, both Black and Osbourne frequently injected profanity into their scripted lines during recording sessions. Instead of rerecording these, the development left these in the game, but included the option for a profanity content filter to be enabled by the player to "bleep" out these words and mask such word on screen using the Parents Music Resource Center "Parental Advisory" label, an icon that Schafer considered to be part of the history of heavy metal. A similar filter exists for gore in the game, preventing any dismemberment and disabling blood in the game. Schafer stated the filters were added to the game in consideration of older players that may not wish to see such aspects, or for parents who opt to play the game with younger children. During development, Schafer stated that while he could not confirm what other musicians and bands would be in the game, there would be more than already stated, and that these musicians were "especially conducive to character creation" due to the amount of theatrics used in their concert shows.

Kyle Gass, Black's collaborator with Tenacious D, voices and lends his facial likeness to a neurotic cannon operator in the game. Comedians David Cross, Steve Agee, Brian Posehn, and actor Wil Wheaton have also provided voice work for the game; Posehn had previously worked with Schafer on their high school newspaper. David Sobolov was also confirmed as a voice actor for other roles in the game; Sobolov noted that he recorded his lines separate from Black's despite his characters' having direct interaction with Riggs. 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.

According to Schafer, Brütal Legend had been in development since 2007, prior to the completion of Psychonauts. Schafer noted that in Psychonauts, they attempted to bring together a lot of assets, including characters and environments, but were not able to successfully integrate them on their first attempt and had to start over on the development of some. In several cases for Psychonauts, changes made in gameplay required them to return and redesign levels to account for the new features. The company decided at the start to use the scrum development approach for Brütal Legend, which they found worked well with their company's culture, allowing them to quickly arrive at playable targets at every milestone. For example, the team was able to bring about their terrain engine, renderer, and a playable Eddie Riggs within a month of development, and by the third month, the ability for Eddie to drive about the terrain, running over hordes of enemies.

Schafer stated that they began the development with the character of Eddie, and recognizing what he should be doing in the game—specifically, swinging around his axe, playing his guitar, and driving his hot rod. Once they found this combination of elements to work well in combat and general gameplay, they were able to expand out the rest of the game from there, as these elements provided a means of testing the game to make sure it remained enjoyable. The first major feature developed for the game was the multiplayer element, given that no previous game from Double Fine had included this feature, and was the highest risk element to the game. The multiplayer gameplay itself was inspired by older strategy games, in particular, 1989's Herzog Zwei; in this game, the player controlled a transforming aircraft mecha that would normally fly about the field to issue orders for constructing new units, airlifting units to other areas, and directing combat, but the player could opt to transform the craft into a giant robot and engage directly in combat. For Brütal Legend, Schafer kept the same concept of a split-mode RTS, but wanted more focus on the ground combat; instead of spending 90% of the time controlling units as in Zwei, the player would only spend about 30% in this fashion within Brütal Legend. This subsequently led to much of the action and combat-driven gameplay outside of the stage battles. In a 2015 interview, Schafer said that much of the gameplay outside of stage battles were to provide tutorials for the Stage Battles, and to make the game more of an action-adventure than an RTS to avoid the stigma that impacts sales of RTS games. This caused the production to expand considerably around the merger of Vivendi-Activision, and Double Fine had difficulties convincing the new publishers to fund the expanded game.

The team used Unreal Engine 2.5 to build and test prototypes of the real-time strategy elements, allowing the designers and gameplay programmers to commence work while another team focused on creating a new game engine. 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. The game-world's large size and varied content necessitated a game engine with streaming capabilities, allowing the game to seamlessly load and unload content as needed — this was also something the team had no prior experience with. Double Fine developed several in-house tools to help streamline the content-creation process for the game's world: an automated testing bot, RoBert (so named after one of the test engineers), was created to put daily builds of the game through continuous and rigorous testing, automatically reporting any errors to developers, while the Multi-User-Editor allowed the game's artists to simultaneously work on the game-world without fear of overwriting each other's work. The team ran into content management issues late in the game's development as more of the game's assets neared completion. 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. With the help of the engineering team, they were eventually able to overcome the performance issues and re-optimize the content for space.

With the popularity of the Guitar Hero and Rock Band franchises, many wondered if Brütal Legend would take advantage of these games' guitar-themed controllers. Schafer mentioned that while he had entertained the idea, he could not find an acceptable way for players to repeatedly switch between standard and guitar controllers, so he abandoned it. Players who preordered the game through GameStop were able to unlock a special promotional in-game guitar designed in conjunction with Jack Black's band Tenacious D, and includes voices provided by both Black and Kyle Gass.

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. However, even when the fate of the publication of the game was unsure, the team continued to work on its development. Schafer reflected that the time spent during development without a publisher was beneficial, allowing them to design the game without pressure from the publisher's goals. EA CEO John Riccitiello, when asked about EA picking up Brütal Legend for distribution prior to December 2008, commented that "Sometimes significant creative risks end up being some of the world’s best products".

When rumors of a possible Wii port arose in March 2009, Schafer stated that "We are making an Xbox 360 and a PS3 version of Brütal Legend." However, according to Ben Fritz at Variety, another studio has been engaged by Electronic Arts to bring the game to the Wii, albeit at a later date than the other console versions, suggesting that it may follow the same model as Dead Space: Extraction, a Wii title scheduled to be released about a year after Dead Space's first release. However, further industry rumors, which claimed that the Wii version was being done by Electronic Arts in-house, have stated that the effort to port the game to the Wii has been canceled due to quality and technical concerns.

Initially after its release, Double Fine had not planned on a PC version of the game, as Schafer has stated that the game is primarily an action game and "meant to be on a console". However, in February 2013, Double Fine announced that a Windows version of the game will be released on February 26, 2013. The Windows port has been updated for higher resolutions of modern computers, and includes both DLC packs released for consoles. The multiplayer aspects of the PC version include a number of tweaks that Double Fine had tracked that they wanted to have made to the console version but could not do; while the full list of changes are not expected to be present in the initial PC release, Schafer has stated that if sales of the PC version are successful, they will look at adding new units, factions, and gameplay modes that they had originally scoped out for the console version. Mac and Linux ports were released in May 2013, premiering as part of the Humble Double Fine Bundle.

Double Fine believed they were given the go-ahead to develop a sequel to Brütal Legend after the game's release, and had invested a great deal of development time towards this, but were later told by EA that it was cancelled. Schafer stated that the sequel would likely incorporate much of what they had to drop prior to the game's release. This game world would have been three times larger than what Brütal Legend contained. The sequel would have likely included a fourth faction that was cut from the original game which would have been the last major group the player would have to fight through, including a major boss character, before the final battles with Doviculus. Schafer further noted that at the end of the original game, Doviculus' head falls into the Sea of Black Tears, and implied that the same effect that the Sea had on Ophelia could happen to Doviculus. Schafer also had ideas for a plot using a character voiced by Ronnie James Dio, but will not likely be used due to Dio's death.

The cancellation of the sequel nearly ruined Double Fine, as they had invested all current efforts toward the title. 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, 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. Upon hearing of the cancellation of the sequel, Schafer and his team began to promote these games around, and were able to obtain publishing deals for all four titles. The games will be able to take advantage of the custom game world engine and other assets they had created for Brütal Legend. The titles were considered financial successes, allowing Double Fine to recover and pursue further game development though steering away from major AAA releases.

As of 2013, Schafer is still interested in a sequel to Brütal Legend, but would require appropriate funding and resources to make it happen as an independent developer. Since then, Double Fine launched a successful crowd-funded drive for Psychonauts 2 in December 2015; Schafer said that if that game does well, there is a good chance that a sequel to Brütal Legend would be possible. Tim Schafer said June 13 during an appearance at E3 2017 that Brütal Legend will eventually get a sequel.

Brütal Legend was originally to be published by Vivendi Games' subsidiary Sierra Entertainment. In 2008, Activision merged with Vivendi's game division (which included Blizzard Entertainment) to become Activision Blizzard, gaining the rights to publication of Brütal Legend. Upon evaluation of their assets, Activision Blizzard chose to drop Brütal Legend along with several other games, leaving the project in limbo. Activision CEO Bobby Kotick later claimed the reason for dropping the project was due to: the project running late; missing milestones; overspending the budget and not looking like a good game. Double Fine themselves were unaware that Activision had chosen to drop the game, having been informed through an Activision press release that omitted the game from their upcoming release schedule, according to studio producer Caroline Esmurdoc. Industry rumors suggested that Electronic Arts was interested in publishing the property, and it was confirmed in December 2008 that Electronic Arts would publish the game. During the period when Brütal Legend's fate was unclear, Schafer was not able to talk about the project to avoid causing problems with any potential business deals.

In February 2009, Activision Blizzard had asserted that the Electronic Arts deal was invalid, believing that they were still in negotiations with Double Fine to publish the game. It was believed that Activision was seeking monetary compensation in a similar manner as it received from Atari for Ghostbusters: The Video Game and The Chronicles of Riddick: Assault on Dark Athena, games that were dropped when Activision Blizzard re-evaluated their assets. On June 4, 2009, Activision filed suit to prevent publishing of the game, claiming that they had invested $15 million in the title and still had a valid contract to release the game. Activision's suit also contends that Double Fine had missed a deadline for the game last year, requesting more time and an additional $7 million in development fees. Activision's considers both the loss of the money they spent on the game as well as potential sales and Brütal Legend-related merchandise as part of the harm done in the lawsuit.

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. The countersuit stated that Activision had dropped the game after its merger with Vivendi and a failed attempt to convert the game into a Guitar Hero sequel. Schafer was infamously quoted as saying, in commenting on their actions, "Hey, if Activision liked it, then they should have put a ring on it. Oh great, now Beyonce is going to sue me too."

In late July, the presiding judge, Los Angeles Superior Court Judge Craig Karlan, reported that a preliminary ruling that could have affected the game's release would have been given on August 6, 2009, with Karlan tentatively ready to deny Activision's motion to delay the game. However, prior to the ruling, the companies announced they had reached an out-of-court settlement on the lawsuits, though details were not available.

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. Activision's lawsuit had been filed at the time the game had reached the alpha release state, and would need to be concluded prior to the game's final release; this required the executives to dedicate their time towards information gathering, interviewing, and other legal matters "during the crunchiest, most critical time of development". As such, while they ultimately were able to settle the legal matter, Esmurdoc believed that the impact of the effort in settling the lawsuit impacted the quality of the final product. Schafer wrote more than 50% of the game's dialog in the few months following the completion of the lawsuit and prior to release, a "big crunch" for him.

Schafer, prior to the game's release, stated that Double Fine had "something awesome" planned for downloadable content to further support the game after release. Two downloadable packs have since been released. The first, "Tears of the Hextadon", was released in early November 2009, containing two new multiplayer maps and a new single-player weapon. The pack was initially free on the PlayStation Network for the first two weeks of release. The second pack, "The Hammer of Infinite Fate", was released in mid-December 2009, and in addition to new multiplayer maps, expands the single-player experience by incorporating new weaponry for the Deuce, outfits for Eddie, a GPS system to track collectibles in the game's world, and other additional content, including figureheads of Razputin, the lead character from Psychonauts, and Schafer himself.

Brütal Legend was announced in October 2007 through a feature article in Game Informer; gaming journalists had received a vinyl record from Activision that contained a backwards message alluding to the game's story. The game's release in October 2009 was promoted as "Rocktober" in official literature about the game from Electronic Arts. 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. A series of short online videos featuring Black (and Schafer in two instances), entitled "Brutal Thoughts with Jack Black", have been used to promote the game since May 2009. At the 2009 Video Music Awards, Black appeared in cosplay as Eddie to promote the game.

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. It has also been announced that Brutal Legend was the official sponsor of the 2009 Mastodon/Dethklok tour. Schafer appeared on Late Night with Jimmy Fallon on October 2, 2009 to promote the game. Black appeared on Jimmy Kimmel Live! on October 14, 2009, dressed as Eddie Riggs and staying in character during his interview.

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. The demo became available to all Xbox Live Gold users on September 24, 2009, and to Xbox Live Silver users and all PlayStation 3 users the following week. The demo is based on the game's beginning, showing Eddie's arrival and his encounters up until the first boss character fight.

Brütal Legend features 107 heavy metal tracks from 75 different bands, selected by Schafer and Music Director Emily Ridgway, each song being a "completely sincere choice" by Schafer and Ridgway, with the whole track list being "designed to be loved by Metal fans." Schafer sought to include songs from most main subgenres of metal, including classic heavy metal, industrial metal, black metal, and doom metal, with each faction in the game favoring a specific type. Though Schafer and others on the Double Fine team had vast knowledge of specific types of metal, Ridgway turned to a used-CD store owner named Allan from Aquarius Records who had "encyclopedic knowledge" of the entire genre, and who provided the team with sample CDs to help them discover some of the more obscure metal bands. 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. Schafer also credits Black with some of the music selections for the game. Instead of relying on labels or bands to provide them with a list of possible songs to select from, the development team sought permission to use specific songs they wanted in the game. In some cases, obtaining appropriate licensing proved difficult, as for songs from bands that had long split up, Double Fine needed to contact each band member to gain permission. This proved to be valuable, as some original bands were excited about their music being used in the game; in one case, Lita Ford was able to provide the game with a song with slight modifications to the lyrics from a version that she was about to release. One song is from the in-game band "Kabbage Boy" for which Eddie is a roadie at the start of the game.

Schafer had tried to get music from groups like Metallica and AC/DC, but their licensing fees were too high. He further tried to work with Iron Maiden, but the group was hesitant to participate after recognizing that the character name "Eddie Riggs" suggested an attachment with the band's mascot, named "Eddie" and designed by Derek Riggs; the band's marketing group pointed out that this could imply that Iron Maiden had endorsed the game.

In addition to licensed music, the game includes over 70 minutes of original score by Tim Schafer's long-term collaborator Peter McConnell. McConnell composed pieces for orchestra and Metal band to tie in with the licensed music in the game. Also, the in-game soundtrack contains an instrumental drum track played by Slough Feg drummer Harry Cantwell, all other "real" drums (6 tracks) were played by Y&T drummer Mike Vanderhule and recorded by Jory Prum. The solos triggered by the player during the game were composed and recorded by Judas Priest guitarists Glenn Tipton (Eddie's solos) and K.K. Downing (Ophelia's and Doviculus' solos). While Schafer would like to have a soundtrack album for the game, he stated that there were already difficulties in securing the licenses for songs within the game and was not sure if it would be possible to extend them to a soundtrack. 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.

The full soundtrack remained intact for Brütal Legend's addition to the Xbox One backwards compatibility catalog in September 2018; Double Fine had assured all music licensing rights had remains in place for this release.

^a The track is merged with the song "More Than Meets the Eye".

Brütal Legend received positive response from gaming journalists, with reviewers praising the story and characters of the game, and driven vocal performances of the voice actors, particularly Black and Osbourne. Daemon Hatfield of IGN felt Black was "completely committed" to the role of Riggs, while Giant Bomb's Ryan Davis found it relieving that Black reined in his typical "loud-talking heavy-metal goofball" act that he is known for and instead performed well, "bringing just the right amount of working-man's matter-of-fact-ness to the role". Osbourne's role was considered "amazing (and surprisingly coherent)" by GameSpot's Giancarlo Varanini and "played brilliantly" by Computer and Video Games' Andrew Kelly. The full cast was commended for their roles; the heavy metal musicians were effective at playing themselves in the game, while the other voice talent performed well and "[did] their part to balance out the star power" in the game. The strength of the characters was considered to be enhanced by the quality of writing of the story, and the use of facial animation. Eurogamer's Christian Donlan considered the characters of Brütal Legend to be the strongest aspect to the game, distancing the title from other video games due to "rounded, personable leads who are distinctly superior to the usual throngs of cybermen and super-vixens", and a facet of Schafer's signature work. Wired's Chris Kohler further attested the strength of the game's story to Schafer's skill, considering that "After Brütal Legend, he should be considered one of the best storytellers in gaming, period." 1UP.com's Justin Haywald noted that the game lacks the ability to review cutscenes, forcing the player to restart the story if they wanted to see these again.

The heavy metal-inspired world of Brütal Legend was also well received, and considered to show a clear reverence for the genre. Gerald Villoria of GameSpy considered the game to be "dedicated to an unabashed love of metal" and "heavy metal fan-service to the highest degree". 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. Critics found that while the graphics for the game may not be the most sophisticated for the current console generation, the detailed art aspects of the world were impressive; Varanini considered that "no matter where you are in the world, there's always some cool object to look at", while Donlan considered the world to be a "constant unfolding delight". The incorporation of heavy metal music into the game also benefited the game. Both Kelly and Villoria considered the soundtrack essential to the game, and praised the moments where specific songs, such as Dragonforce's "Through the Fire and Flames" would be used as background music during specific game sequences. Kelly further praised the game for using the songs to define the action of the game instead of relegated to random background music. Villoria also considered the soundtrack to have "enormous breadth of sound and diversity", introducing the player to heavy metal genres they may not have known even existed. G4TV's Jake Gaskill considered listening to the soundtrack to be the equivalent of "taking a class in heavy metal appreciation."

The actual gameplay was seen as Brütal Legend's largest weakness. Many reviewers were critical of the incorporation of real-time strategy (RTS) elements into the game, a fact that was not well advertised prior to the game's release and does not become apparent to the player in the first hours of the game. Though Schafer had set out to make the console-based game like an RTS from the start, they were warned by both Vivendi and Electronic Arts that "RTS" was "a naughty word in the console space", and instead marketed it as an action game. Despite this, reviewers found that the game was still difficult to play on a console due to the selected controls that made it difficult to target objectives or troops, the lack of a mini-map to track friends and foes, and the frantic pace of battle.

Critics did appreciate the slow introduction to the various aspects of the game as part of the single player game, but felt the game did not adequately introduce or explain all of the game's RTS features, such as the ability to mount a final stand on one's stage. Some also considered the single-player campaign Stage Battles to be too easy, winnable by brute force, 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. The mix of gaming genres between the RTS and third-person action was found particularly confusing; Kohler commented that the handling of the individual genres was accomplished well, leading to "an astoundingly complex design instead of a simple one" that diminished the enjoyment of the game, while Davis considered that "perhaps there wasn't enough confidence in any one piece to let it carry the whole game". However, some felt that the various genres helped to create "a variety of gameplay opportunities", and made for "rather elegant" Stage Battles. 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. Though some critics argued that stripping out the RTS elements and leaving an action combat game wrapped in the metal-themed world would have been a better game, Schafer countered that this would have not been true to the vision that he had from the start. Schafer would later jokingly refer to the RTS elements of Brütal Legend; during the fundraising for Broken Age, Schafer teasingly threatened to add RTS elements to the point-and-click if the funding had reached certain levels.

Gameplay outside of the Stage Battles was also met with mixed impressions. Most considered the side missions highly repetitive, which included mission types that are generally disliked by gamers, such as escort missions. 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. The information about the world that players can access in the game's pause menu was also found to be lacking, neither showing the collectible elements of the game on the main map, nor easily identifying the alliance of the various troops in the in-game guidebook. Though Eddie gains the ability to fly during Stage Battles, the inability to use this or to make the character jump led to reviewers getting the character stuck on the landscape at times when exploring. Some reviewers found the number of progress checkpoints in the game to be lacking, requiring the player to repeat a long mission if they should die before reaching one. The single-player game was also considered to be short, lasting as little as four hours if one only completed the main story missions. In 2011, readers of Guinness World Records Gamer's Edition voted Eddie Riggs as the 48th-top video game character of all time.

According to the NPD Group, Brütal Legend sold approximately 215,000 copies in the United States in October 2009, with about 150,000 copies being for the Xbox 360 platform, making it the 12th-top-selling game in that month. These numbers were not considered to be strong, and were attributed to the difficult marketing of the game, which emphasized Jack Black's involvement and the heavy metal nature of the game, but did not assert what the gameplay would actually be like, with the possibility that the mention of the RTS elements of the game would have possibly driven more players away from the game. In an interview in February 2011, Schafer claimed that the game had sold over 1.4 million copies.

According to data collected through Nielsen SoundScan, some songs contained within Brütal Legend's soundtrack saw digital sales increases of up to 700% following the game's release, similar to the effects of Guitar Hero and Rock Band, though impact on overall sales of these songs was rather small.

Black was given the Best Voice award at the Spike Video Game Awards 2009. During the 13th Annual Interactive Achievement Awards, the Academy of Interactive Arts & Sciences awarded Brütal Legend with "Strategy/Simulation Game of the Year" and "Outstanding Achievement in Soundtrack"; it also received nominations for outstanding achievement in "Character Performance" (for Eddie Riggs), "Original Story", and "Game Direction".

The game was also nominated for the Game Developers Choice Awards for "Best Writing" and "Best Audio".

• Full Throttle, an earlier Tim Schafer game featuring bikers and heavy metal music

Wikiquote has quotations related to Brütal Legend.

• Official website