[1][6][7] In terms of musical notation, the song is composed in the key of D-flat major, with a tempo of 184 beats per minute.

"The remake manages to do justice to the original, and may even be a little more believable, thanks to Aespa's sweet, girlish charms", she added.

[9] Writing for Hypebae, Ye-eun Kim described "Forever" as a "fresh, love-themed track" that shows a "completely different side of the virtual hybrid K-pop group".

[7] Irene Chou of The Brown Daily Herald called it "a soft ballad's late-winter feel" and praised the group's "impressive" vocals atop the "flawless execution of eye-catching choreography".

[11] An accompanying music video was uploaded to SM Entertainment's YouTube channel on February 5, 2021, and has accumulated more than 46 million views on the platform.

[17][14] During the group's attendance at the Second World Cultural Industry Forum (WCIF), Aespa performed the single along with "Black Mamba" and "Next Level" on a stage combing AR and XR technologies.