The band and their sound engineer, Dave Auchenbach, recorded the album in a house in Providence, Rhode Island directly onto a 2 track DAT master tape. The album is a clear continuation of the sound they established on their previous albums, featuring a very dense sound composed almost entirely of distorted, often-processed bass guitar; loud, fast drums; and indiscernible vocals buried in the album's mix. The album's artwork was drawn by Brian Chippendale; the album's title was not decided until after the artwork was finished.
Hypermagic Mountain was met with near-universal acclaim, with an average of 88 out of 100 based on 23 reviews on Metacritic. The same site rates the album at number 42 on the all-time highest rated albums, and as the fourth best album of 2005.Stylus Magazine's Rogue Strew hailed the album as "another stride toward the perfection of [Lightning Bolt's] prog-noise esthetic", while Prefix Magazine's Aaron Richter called it Lightning Bolt's "most accomplished effort to date, one-upping 2003’s Wonderful Rainbow with a fresh sense of maturity."Pitchfork's Brandon Stosuy similarly described Hypermagic Mountain as the band's "most well-oiled album", but criticized that "somewhere in the middle a lack of variety creates a dull patch." Joe Martin, in CMJ New Music Monthly, said that the album's "craft-refinement has an exhilaration all of its own".