 The episode received mixed reviews from critics. Bobby Hankinson of the Houston Chronicle and E! Online's Jenna Mullins were pleased by how "Comeback" reminded them of early episodes of Glee — Mullins hailed the return of familiar characterization, and Hankinson commented: "It felt like old times, and it felt good." Though he observed that the episode was light on plot, Hankinson praised the writing and comedy. CNN's Lisa Respers France found the episode's title apt, as Glee was "firing on all cylinders" with little room for improvement. Erica Futterman of Rolling Stone was "pleasantly surprised", as she had anticipated a decline in quality from the previous episode, and Kevin Fallon of The Atlantic commented that apart from the Bieber jokes, "the rest of the episode was sharply written and loaded with self-referential jokes". Other critics found "Comeback" mediocre. Entertainment Weekly's Sandra Gonzalez wrote that it was "a bit off", The A.V. Club's Todd VanDerWerff felt that "something was missing, making the whole thing stultifying, lifeless, and boring", and Robert Canning of IGN deemed it "fine and inoffensive", but ultimately forgettable. Amy Reiter of the Los Angeles Times was "a little disappointed" in the episode for a lack of substance, creativity and emotional maturity. James Poniewozik of Time deemed it amongst his least favorite episodes, for "not even [being] bad in a memorable way". He noted that "Comeback" was "essentially a collection of subplots", and questioned its purpose.
