The song was released for free digitally on May 23, 2018 through Adult Swim's 2017 singles series,[2] marking Sleep's second entry following 2014's "The Clarity".

[5][6] Musically, "Leagues Beneath" is a long, slow epic that begins with B-tuned guitar and gradually builds by introducing new elements.

After the song's protracted crescendo, it concludes with a somber passage where layers strip away and give way to clean, psychedelic string sounds.

[7] Phil Witmer of Vice praised "Leagues Beneath", writing that it is "possibly bigger than anything on The Sciences",[7] and Brock Thiessen of Exclaim!

"[9] At nearly seventeen minutes, "Leagues Beneath" is the group's longest track since 1999's "Dopesmoker" and, by some metrics, constitutes an EP.