"Midnight" was built over a previously unreleased original track produced by Jon Hopkins in 2003. The track, named "Amphora", was never completed by Hopkins and was partly released by ambient/electronic music blog A Strangely Isolated Place on SoundCloud in early 2012, as part of their playlist "ASIP - 1.00.00". The song also incorporates elements from a Jon Hopkins recording titled by Hopkins as "The Fourth State II", a reproduction of his 2008 extended playThe Fourth Estate.
The song received mostly positive reviews from critics, who noted a change in the sound of the band and drew comparisons to Bon Iver and Justin Vernon. Al Horner of NME approved of the band's new musical direction and lauded the song as a "dive into icy electronic experimentalism".Contactmusic.com's Lauren James similarly praised the song, writing: "gone are the crashing pianos, guitar and soaring vocals of the Brit rockers' more famous ballads, replaced with a pared back, minimalist electronic song". Micahel Nelson of Stereogum concurred, commenting that the song brought out Coldplay "at their most spacious and ambient, stripped down to a ghostly essence." Writing for PopMatters, Evan Sawdey rated the song 8/10 and summarized it as "chilly, this moody, and evocative".Rolling Stone 's Cory Grow compared Martin's vocals to Peter Gabriel "as he sings about darkness, while the synths build throughout the track before a skittery, rave-like keyboard line flits about noisy static".Idolator's Carl Williot described the song as "a haunting electronic soundscape that not only lacks the band's trademark anthemic choruses and stadium-filling guitar lines, but boasts nary a hook and has few decipherable lyrics". Lewis Corner of Digital Spy opined that the song was "subdued, murky, twinkling, but definitely not lead single material on first listen" and hailed the band for "never fail[ing] to shake up their sound and become even more successful with it." Jamieson Cox of Time magazine felt the song "never blossoms into one of Coldplay's trademark climaxes, instead blurring into a phosphene cloud of synth melodies" but praised it for being "another step in a new direction for a band that's never been content with staying in place".
The music video for "Midnight" was noted for its use of night vision filters.
A 5-minute music video for "Midnight", directed by Mary Wigmore, was premiered on music videohosting serviceVevo at 6pm UTC (Midnight in Ulaanbaatar, Mongolia time), on 25 February 2014. The video was shot nearly in its entirety in thermal infrared imaging and negative imagery, incorporating various visual effects. The thermal infrared camera was a FLIR SC8303 with either a 25 or a 50mm prime lens, depending on the shot. The lenses were made by Janos Corporation. The wavelength range is 3 to 5 microns, or mid wave infrared. The thermal infrared video was recorded as HD-SDI on an Atomos Samurai Blade with a 480 GB solid state hard drive. Simultaneously, raw digital video was captured at 30 frames per second into FLIR ExaminIR software. The video was watched over 1 million times in less than 24 hours after it was posted on their Facebook page. Just two days later it reached 3 million views, later passing 13 million views on 21 April 2014.
The remix version of the song has received positive reviews from music critics. Kory Grow of the Rolling Stone magazine wrote that Moroder turned an understated EDM track into a "dance floor banger" and "eight-minute affair with no time squandered": "One of Coldplay's most unassuming tracks off their forthcoming record Ghost Stories is now its most danceable." He also commented that the producer "adds a pounding bass-drum beat from the onset and then uses the synth filigrees toward the end of the track ... to build it into something that would have once backed Summer. Vocal 'aahs' and soft pads of synths, alongside robotic chanting in French, make the track more Moroder than Martin for the final four minutes."
Mikael Wood of The Los Angeles Times wrote in similar tone, "The producer's lengthy reworking, which climaxes in a surging synth fantasia complete with robot voices, adds some verve to Coldplay's rather sedate original." Tom Breihan of Stereogum noted that while the remix "might not have the same spacey majesty as peak Moroder, it still does a nice job translating the inward sweep of the original track into an orchestral disco pulse."
According to Ryan Kristobak of The Huffington Post, Moroder transformed "Midnight" into "a dance-floor hit, without abandoning the song's Brian Eno/Bon Iver-influenced ambience."Idolator's Robbie Daw commented, "Here Moroder lays a hypnotic click-click-click disco beat below the Kid A-esque atmosphere of the track, and the whole thing eventually builds into a tornado of majestic synths and menacing piano chords. And, of course, no modern day remix by Giorgio Moroder would be complete without the addition of his own ghostly robot vocals."