[8][7] Brittany Spanos of Rolling Stone stated Rae "is on a pop hot streak" with the single's release, calling it "dreamy" and "entrancing",[9] while Billboard's Jason Lipshutz wrote Rae's "pop aesthetic is coming into focus" describing it as "dextracting the breathy flirtations from previous single 'Diet Pepsi' and applying them to a sleek, futuristic dance-pop sheen.

"[10] Gabriel Saulog of Billboard Philippines wrote that the song embraces and breathes new life into its "'90s Eurodance influences –– complete with twinkling synth elements, steady club beats, and Rae's soft yet dreamy vocals that evoke a sensual (if provocative) nature" noting that its reminiscent of Madonna's Ray of Light (1998) and "rightfully" solidifies "her status as a rising figure in today's pop landscape.

"[11] Michael Kearney of Earmilk praised Rae's "refreshing and bold" sound, writing that "Aquamarine" is a "sparkling, dance-driven track that blends sensual, aquatic themes over a sweeping four-on-the-floor beat," comparing its "nostalgic 90s-inspired synths" specifically to Madonna's "Nothing Really Matters" (1999) and Spears' "Breathe on Me" (2003).

[12] Spanos described "Aquamarine" as "dazzling and hypnotic" while commenting on Rae's reinvention as an artist: "She aligned herself with the music and fashion world's most beloved avant-gardists — Charli, Arca, Rosalía, Petra Collins, Interview Magazine's Mel Ottenberg and Dara Allen — who helped bring her vision to life everywhere from music videos to remixes to surprise performances at Madison Square Garden.

The video progresses with her dancing with a chair on the street, interspersed with clips of Rae, wearing a sparkly dress, atop a bridge.

The idea of collaborating with Venezuelan producer Arca came after a 2023 Vogue interview with Rae, saying that she would love to work with her and is a huge fan of her music.