As of June 2016, the album had a score of 82 out of 100 from Metacritic based on "universal acclaim". "Alternative Press" gave the album a perfect score of all five stars and said it "takes multiple listens to absorb, and, even then, you're probably not going to have a clue to what Bixler's raving about." Yahoo! Music UK gave it a score of eight stars out of ten and said it was "not an album to listen to casually. It insists on taking over your life for an hour, demands a level of concentration rare in rock, amply repays multiple plays." "Under the Radar" gave the album eight stars out of ten and said that the band "has created the antithesis of ATDI, leaving behind any formula or typicality. What they kept was the fire, the fury, and the passion." "Drowned in Sound" gave it a score of eight out of ten and called it "truly exquisite and well worth the wait." Playlouder gave it a score of four stars out of five and said, "There are moments of prog rock, jazz fusion and freakydelia in this rush of ideas and if that sounds awful then don't be put off. Instead of the shambolic mess that this kinda influence normally entails Mars Volta have come strictly disciplined." "Uncut" gave it four stars out of five and said: "Imagine a jam session between King Crimson, Fugazi and '70s Miles. Now imagine it working. That's the Mars Volta." "Blender" also gave it four stars and said it "Roars like Led Zeppelin, churns like King Crimson and throbs like early Santana." "Tiny Mix Tapes" likewise gave it a score of four out of five and called it "a very strong debut album for the Mars Volta." "Ink 19" Magazine also gave it a favorable review and said it was "definitely worth checking out, but make sure to keep an open mind and check any preconceived notions at the door."