"[11] AllMusic critic François Couture stated that the album "puts the emphasis on sunny melodies [...], but drowns them in glitch textures," summarizing it as "brilliantly conceived and masterfully executed" but also noting that the result "strikes and disconcerts.

called it "the electronic album of the year" and stated that "Fennesz processes and manipulates the source material by taking the pulse of the pop tune and rebuilding something deeply sentimental and sweet.

"[15] Reviewing the album's 2006 reissue, The Boston Phoenix's Matthew Gasteier called Endless Summer "a turning point in experimental electronic music, the moment when melody and cacophony learned to love one another," and labeled it a "fuzzed-out masterpiece" in the lineage of My Bloody Valentine and the Jesus and Mary Chain.

"[9] Nate Dorr of PopMatters called it "the most pivotal, most accessible, and most strikingly unique point in the Fennesz catalogue so far, and one of the more influential noise albums of the early decade.

"[2] Meggitt also noted the album's references to "the whole discourse of sea-and-surf inspired music, literally evoking the rolling waves with grainy, often turbulent fields of noise," along with the influence of 1950s exotica.