On December 31, 2022, while hosting her NBC live special Miley's New Year's Eve Party, Cyrus announced the release of the new single "Flowers".
[5][6] "Flowers" became Cyrus' second number one single in the United States, hitting the top spot on Billboard Hot 100 on chart issue January 28 and staying there for six continuous weeks.
[13][14] "River" shares the same production team as its previous single "Flowers" – it was produced by Kid Harpoon and Tyler Johnson, with additional writing done by the singer and Justin Tranter.
[15][16] "River" is a dance-pop and synth-pop song with elements of new wave, synthwave, post-disco and acid pop,[17][18][19][20] described by Cyrus as a "dancefloor banger".
[18] George Griffiths of the Official Charts Company described it as a "new wave-esque" tune, consisting of "wonky" instrumental inspired by 1980s synth-pop and electronic music.
[15] Chris Willman of Variety noted the song for the inclusion of "retro synth sounds" and further found inspiration from the style of Giorgio Moroder.
"[26] Alexis Petridis of The Guardian called it an EDM anthem with "an undeniable dancefloor rush," despite its "tendency to flicker between squelchy video game sounds and out of kilter hip hop breaks.
[37] "River" commercially failed to achieve similar success as "Flowers", debuting at number 32 on the Billboard Hot 100, charting alongside four other songs from the album.
[41][42] Sal Cinquemani of Slant Magazine noted the song's "enticing, high-stakes chorus worthy of Cyrus's fierce vocals and personality.
"[19] Pitchfork's Shaad D'Souza called it one of the best songs on Endless Summer Vacation, adding: "Cyrus effectively showcases who she is at this point in her career: Mature but still messy, not above a theatrical turn of phrase ('You're pourin' down, baby, drown me out') and, very occasionally, still in tune with the big-hearted optimism that characterized her earlier music.