Tracks 1–5 Worlds opens with "Divinity", which contains vocals by Canadian singer
Amy Millan, from the bands
Stars and
Broken Social Scene. Robinson chose the track as the opener because it was the first he wrote with a slower tempo and more emotional chords, a style he considered representative of
Worlds. Tatiana Cirisano of
Billboard wrote that there is a large contrast between the intro and chorus; while the former contains "underwater-sounding", smooth vocals, the latter contains a "cacophony" of cymbals and glitch-like sounds reminiscent of video games. Barry Walters of
Wondering Sound said that it features common characteristics of EDM, such as a powerful beat, dense layers of synthesizers, and an airy female vocal, while Elissa Stolman of
Vice described the track as an indie-electronic "festival rave anthem", with synths that resembled M83's "
Midnight City" (2011). Alternatively, Rupert Howe of
Q found similarities to
electronica and M83-like
space rock. The next track, "
Sad Machine", was the first song for which Robinson had recorded his own vocals. Describing it as a "duet between a lonely robot girl and the human boy", Robinson employed
Avanna, a
Vocaloid voice, as the song's lead singer. Larry Fitzmaurice of
Pitchfork considered it one among other tracks on
Worlds which resembled the "high-wire
synth-pop fantasias" of
Passion Pit, as it contained a mid-tempo instrumental and "starry-eyed melodic structure".
Las Vegas Weekly Mike Prevatt identified inspirations from M83 and
Sigur Rós. Lucas Villa of
AXS described the track as "heroic and awe-inspiring" and felt that it evoked the "dreamier" elements of electronic music. The third song, "Years of War", features
Breanne Düren of
Owl City and Sean Caskey of
Last Dinosaurs. Pursuing a "cutesy synth-pop thing", Robinson said it was the hardest he had ever worked on a song. It leans into electropop, synth-pop, and new wave. The song's main instrument is a
trance synth, which Stolman felt contrasted with the song's retro elements, such as a boom-clap rhythm and "sepia-toned synths". The song is followed by "
Flicker", which Robinson considered one of his proudest moments on the album. The song begins with a calm disco beat reminiscent of old video games and a faint bassline building in the background. A female voice enters, speaking chopped-up Japanese phrases. Prevatt said that the song uses a classic
hip hop breakbeat before the chorus, which he described as an "emotional payoff". Just after the two-minute mark, the song switches to a bass-heavy atmosphere, and Buerger comments that Robinson retains his "invitation to the party" in spite of the song's experimental elements. She described the song as the most dynamic on the album. Garrett Kamps of
Spin identified melodic similarities with
Boards of Canada. "Fresh Static Snow", the fifth track on the album, also uses Avanna. Robinson said that the song focuses on his feelings of loneliness and the idea of soulmates.
Consequence of Sound Derek Staples found the song's "ethereal electro vibes" to be reminiscent of
The Glitch Mob and
The M Machine. Stolman described it as a "coiled, metallic guitar squall" which goes to "midrange bass grit" culminating in a heavenly breakdown with melancholy robotic vocals.
Tracks 6–12 The album's sixth track, "Polygon Dust", is a collaboration with
Lemaitre, a band Robinson was fond of. Its main element is a trance synth. Stolman described the track as one of the safest of the album, containing natural vocals as opposed to "Sad Machine" and "Fresh Static Snow", as well as calmer synths. It is followed by "Hear the Bells", which features
Imaginary Cities. It is based on one of the band's existing songs, "Bells of Cologne". Robinson felt that the song is where he sings with the greatest stage presence. Kamps thought the vocal choir was "fantastical and defiantly cheery", while Stolman wrote that the song contains
Givers-like layered
indie vocals and emotional lyrics. Fitzmaurice said that "Hear the Bells" has a good amount of "rocket fuel" due to its dynamic electronics and anthemic synthesizers. "Natural Light",
Worlds eighth track, is an interlude. Robinson enjoyed the track due to its
intelligent dance music passages inspired by artists such as
Aphex Twin and
Venetian Snares. Stolman commented that, despite its driving bass, sharp drum hits, vocal fragments, and sparkling keys, the track could be called minimal in the context of the album. The ninth track is "
Lionhearted", which features
Urban Cone. It was one of the first tracks Robinson wrote for the album, describing it as "anthemic". Critics wrote that this was the album's first display of a faster tempo. Kamps described the sound as "exuberant pop" and Prevatt felt there were similarities to the styles of
Holy Ghost! and Passion Pit. The next song, "
Sea of Voices", went through multiple iterations before its release. It is a five-minute orchestral track that contain no drums in its first minutes, being only composed of synths reminiscent of atmospheric
big room. Noting the late introduction of beats, Buerger said the track has "the emotions of a tear-jerking blockbuster". Kamps found the build-up similar to ones by Sigur Rós. "Fellow Feeling" is
Worlds penultimate track. In a criticism of EDM composition, Robinson starkly juxtaposed what he felt was "beautiful and serene" with aggressive and violent elements. Sharon O'Connell of
Uncut felt that the opening section was reminiscent of
chamber music, that was described by Villa as "cinematic" and Walters as "symphonic". Further into the song, a voice says, "Now, please, hear what I hear", and a strong bass enters. Walters claimed the track is interrupted by aggressive
dubstep elements which O'Connell described as
electro funk that had been
chopped and screwed. Villa named it the album's most climactic moment. The final track, "Goodbye to a World", is the third to use Avanna. Robinson wanted the feeling of a "beautiful apocalypse" for the song. It has lullaby-like moments contrasted with sections that Staples found similar to
breakcore and Stolman characterized as "fist-pumping brutality". == Release and promotion ==