Man on the Moon II: The Legend of Mr. Rager debuted at number three on the US Billboard 200 chart, selling 169,000 copies during its first week of release. Upon its release, the album received generally positive reviews from music critics. On July 26, 2012, it was certified gold by the Recording Industry Association of America, for shipments of 500,000 copies in the United States.
Jim Jonsin compared Cudi's blending of sounds to B.o.B's genre-bending album The Adventures of Bobby Ray, stating "It’s a mix. It’s kind of some club stuff, some hip-hop traditional rap stuff, and then some rock-pop stuff. He’s goin’ everywhere." Cudi later said that Jonsin had misinformed fans about the new album, "I got mad love for Jim but he was misinformed. There is no Kanye & Kid Cudi Duran Duran song, I'd sample a 90s record before a 80s record anyday and when I worked with Jim, I hadn't even started sessions with Plain Pat and Emile yet so the direction of my album was yet to be determined."
Cudi stated that "Man On The Moon II is dark by nature and "instead of bringing you into my dreams like my first album, I'm bringing you into my reality, good and bad. It will explain more of who I am as well as pushing the envelope musically." Cudi also stated he has scrapped the collaborative theme of Cudder for a project that is more personal. He also discusses his former cocaineaddiction on the album. Music critic Matthew Cole, noted elements of rock music on the album and wrote that it "finds Cudi burrowing deeper into the black hole of spacey psychedelia, fusing the clinical, synthetic hip-hop of 808s & Heartbreak with rock sounds derived from Hendrix, Pink Floyd, and Zappa".
The first promotional single titled "Revofev", which stands for "Revolution of Evolution", was released through Kid Cudi's website on June 17, 2010. The song was produced by Plain Pat. The album's first official single titled "Erase Me", featuring Kanye West, was debuted on a Cleveland radio station June 30, 2010 and was officially released to Rhythm/Crossover radio on August 17, 2010. On August 24, 2010, "Erase Me" was officially released digitally on iTunes. On October 25, 2010 the song "Mr. Rager" was officially released digitally via iTunes as the album's second single.
The album debuted at number three on the US Billboard 200 chart, with first-week sales of 169,000 copies. In its second week it crossed the 200,000 sales mark. As of December, 2011 the album had sold 482,727 copies in the United States. On August 6, 2012, the album went gold after selling more than 500,000 copies.
Man on the Moon II: The Legend of Mr. Rager received generally positive reviews from music critics. At Metacritic, which assigns a normalized rating out of 100 to reviews from mainstream critics, the album received an average score of 69, based on 20 reviews.Entertainment Weekly 's Simon Vozick-Levinson called it "a cohesively constructed concept album that will reward repeat listens".Chicago Tribune writer Greg Kot complimented Cudi's themes of "the stoned-and-alone rapper" and stated, "the music is as consuming and intoxicating as the lifestyle Cudi describes". Charles Aaron of Spin commended it for "boldly reshaping Cudi's sound – with vivid production" and stated "The dizzy friction between rap's grasping for control and rock's desire to lose it entirely give Cudi's confessions a dicey, volatile edge".AllMusic writer David Jeffries said that, "just like on his debut, the soundscape is spacy and far-reaching, making this interstellar therapy session a much more interesting transmission. At its best, it’s fascinating".Slant Magazine's Matthew Cole expressed that "the hybrid production style proves an atmospheric and eerie delight" and commended Cudi for his unconventional musical approach, writing in conclusion, "Pursuing genius at the expense of consistency might work out just fine for Cudi: I'm not convinced that he's a good rapper, but I'm pretty sure he's an important one". Mark Beaumont of NME called it "a grungy, filthy record full of angels and demons".Pitchfork Media's Jayson Greene called Man on the Moon II "a bumpy listen", but found it "more fully realized" than Cudi's debut album.
In a mixed review, Michaelangelo Matos of The A.V. Club found Cudi's delivery insouciant and the music merely "listenable", without "much grasp of any of the styles or modes he tries out." Dave Heaton of PopMatters viewed that its "subject matter" is not "delved into as creatively as on the debut album" and stated "Sometimes [Cudi] seems to be falling into the typical trap of sequels: replicating instead of moving forward".Rolling Stone 's Jonah Weiner commended its "dramatic, breathtakingly stark production", but ultimately panned Cudi's performance and stated "he's grown rote in his self-pity and flat as a singer".Jon Pareles of The New York Times viewed that Cudi's rapping "wander[s] away while the track continues without him" and stated "In its utter self-absorption, the album teeters between fascinating and numbing". Nitsuh Abebe of New York called it "a weary and sometimes beautiful catalogue of trying times and overindulgence [...] a melodic take on hip-hop that feels woozy and genuinely passionate, inviting you as deeply into his head as the lyrics. [...] But vulnerability loses its power when it’s calculated to sound dramatic and masculine".