Challenger is Knut's second full-length and, coming four years after the original release of the band's debut album (it was released later in the U.S.), it shows a big leap forward. The first album was actually really impressive, but Challenger outdoes it in terms of being heavier, tighter, more abrasive, and just more punishing in general. Comparable to a cross between Hydra Head labelmates Botch and past touring mates Isis (with a little bit of Meshuggah-style math-thrash thrown in here and there), this album runs the gamut from slow, agonizing grinders (most notably the 19-minute closer, "March") to hyperactive math-metal ("Ice Will"), although sometimes these elements are also combined into the same song. The dissonant guitars, along with frontman Didier's cathartic, throat-shredding vocals, give Knut's music a corrosive edge that's present throughout this album, with the one exception being the desolate, acoustic guitar-based "58.788," which adds a welcome reprieve from the assault. (This track is actually heavily reminiscent of Isis offshoot Old Man Gloom, for those who follow the Hydra Head family of bands closely.) But the rest of this album is relentless, although it could also be considered "cleansing," at least in the same way as drinking a bottle of Drano and scrubbing your brain with a Brillo pad might be.
AllMusic Review by William York