The song received positive reviews from music critics. Crystal Bell of
Nylon described the song as "synthpop siren's call with a deliciously dirty bassline", and that it "highlights each member's vocal charms". Writing for
Consequence of Sound, Mary Siroky named the song as "a high-energy 'sneak peek' track" that offers "a vibrant beat and an earworm chorus". ''
Clash's Robin Murray dubbed the track as a "sparkling, hook-laden return that sits in a synth-pop lane". Mashable'' ranked the song at number 11 in their list of "The 16 best K-pop songs of 2022 (so far)", writing: "To mark the start of their new era, aespa dropped "Illusion," an electronic pre-release track that builds on the group’s synth-pop calling and affinity for sticky, hypnotic hooks".
Rolling Stone's Kristine Kwak stated the song is "a loser to Aespa’s traditional futuristic synth-heavy sound" and called it "a fan favorite and rightfully so". Writing for
Beats Per Minute, Chase McMullen labelled it as the "sort of song that has the power to get you dancing in the middle of a bar, not caring the least about an onlooker as you weave to its every move". Rhian Daly of
NME thought it was "the best song on this record" with "minimal, shadowy verses before hitting a hypnotically lowkey refrain". ==Commercial performance==