[10] The album received reviews that were generally favorable toward the project's wide variety of genres and often surprising selection of contributors, but with some qualms about its repetitive or inconsistent nature as a listening experience.

"[2] Metal Hammer also endeavored to rank all 53 songs on the album, concluding that the best is the version of "Nothing Else Matters" by Miley Cyrus, who was supported by Elton John, Yo-Yo Ma, Andrew Watt, Chad Smith, and current Metallica bassist Robert Trujillo.

[20] Pitchfork also gave the album a mixed review, calling it "enormous and uneven" and criticizing some predictable covers by the hard rock and heavy metal artists, but praising genre-jumping contributions like those by Japanese-British pop singer Rina Sawayama and Ghanaian-American musician Moses Sumney.

also noted that not all of the 53 songs are fully satisfying, but praised the project for its contributions to charity while ranking Washington's version of "My Friend of Misery" as the album's best track.

"[15] NME called it "a fitfully thrilling hodgepodge" that forces the listener to choose their own favorite version of each song, but concluded that the album is "a fantastic tribute to one of metal's sacred texts.