Azalea raps the track's aspirational lyrics with a mantra technique, pertaining to themes of perseverance, empowerment and underdog triumphalism.
[2] On 24 February 2014, Azalea announced the song as a promotional single that would serve as an "instant grat" digital download from the iTunes Store pre-order of The New Classic.
[9][11] It features a tinkering beat[12] produced by tuned percussion instruments including chimes and a glockenspiel which causes eerie loop sound effects in the song.
[8][12] According to Lucy O'Brien of The Quietus, the lyrics portray Azalea as "the hardworking Aussie girl and the feminist goddess urging with messianic fervour".
[18] Similarly, The Line of Best Fit's Laurence Day felt the track manifested the rapper as "an affable bundle of chum-ly charm with lessons (not patronising lectures) that are applicable for anyone with a lick of ambition".
[27] Craig Mathieson of The Sydney Morning Herald praised the song's "unexpected complement" of inspirational lyrics with spectral melodies.
[11] Idolator reviewers were divided; Carl Williott deemed the song "a thudding piece of inspirational rap",[5] while Christina Lee wrote that it was "tepid" and hinted at "'storms' and 'goals' like posters in a school guidance counselor's office".
[28] Other reviewers were also critical of the track's lyrics; Alfred Soto of Spin said it "lays out every admonitory cliché from the Barnes & Noble self-help shelf"[14]—a view echoed by Lindsay Zoladz of New York who dismissed it as "inspirational quotes copied from a high-school guidance counselor's bulletin board".
[29] Karen Lawler of Blues & Soul wrote: "While, [the track is] is bound to be a favourite among Iggy fans, it's a subject that's been done millions of time before and it's been done better".
[31] "Impossible Is Nothing" was named as one of the two worst songs on The New Classic by Devone Jones of PopMatters who criticized Azalea for "literally preaching—to youths, rather than [relating] to them".
[34] While Troy L. Smith of The Plain Dealer felt Azalea "[showed] promise" with the song; he dismissed the production as "leftovers from one of Eminem's recent albums".