"Porque te vas" is a romantic ballad[17] that incorporates elements of funk, disco and pop music, featuring a predominant use of the saxophone.[18] Critic Julin Molero of Lafonoteca described the track's instrumentation as "full of self-confidence with almost mocking interventions of the brasses and the crash of the drums releasing unexpected blows".[19] Writing for the Spanish edition of Rolling Stone, Miguel ngel Bargueo wrote that the song possessed "an unruly rhythm and distinctly pop sound".[20] In the book Lost in the Grooves: Scram's Capricious Guide to the Music You Missed, authors Kim Cooper and David Smay described the song as: "delicate breezy pop with one of those super-suave catchy tunes".[21] The organizers of Festival Europa Sur stated in 2014 that with tracks like "Porque te vas", Jeanette "demonstrated that a cancin meldica song can be approached from a pop optic".[22] Her vocals have been described as "innocent",[23] "mischievous",[24] "sweet",[24] "sultry" and "angelic".[21] Julin Molero felt that Jeanette's voice, "this time moves a bit away from the usual sweetness to become a childish and playful air."[19]