Binary Code contains the lead single "Black Mirror", a rock version of their debut song "Valkyrie", and three new tracks. Group member Ravn co-wrote the lead single "Black Mirror".[1]
The EP ranked at number 2 for the weekly Gaon Album Chart[2] and number 4 for the monthly chart.[2] The EP sold 103,240 copies in South Korea by the end of June 2021.[3] Nearly four years after release, it re-enter the weekly chart, now re-named the Circle Album Chart, in January 2025 at number 20 with 5,001 copies sold in the week.[4]
Black Mirror was listed as one of 'The Best K-Pop Tracks of 2021' by Dazed. Dazed stated "There's the slap of funk bass and washes of strings, elements that comprised the backbone of 1979's Off The Wall, but ONEUS's composers have recalibrated the analogue into a cool, impersonal sheen of digital production. It's a canny twist; a thumping, computerised nu-disco backdrop for the song's flesh and blood lament – the loss of human connection within the technological age."[5]
Puah Ziwei, writing for NME, noted that the lead single "Black Mirror"'s music video "seem to draw inspiration from the late Michael Jackson" and the "lyrics also reference a number of the late pop icon's hits, including 'Bad' and 'Man In The Mirror'."[1]
