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 peak' 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". In Billboard, reviewer S.B. wrote that the song is a "sinister track [that] continues to explore the group’s cyber-futurism theme". 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".
