On Metacritic, Alpha Zulu received a score of 84 out of 100 based on 16 critics' reviews, indicating "universal acclaim". Helen Brown of The Independent felt that the album "is packed with an impressive amount of energy and ideas for a band celebrating their 25th anniversary" and "all 10 tracks are stacked with hooks, making it as good as their 2009 breakthrough album, Wolfgang Amadeus Phoenix". Writing for NME, Thomas Smith called it an album "that further confirms their place as one of the scene's most consistently enjoyable bands" with "nods to the razor-sharp pop hits from their beginnings ('If I Ever Feel Better'), to the indie-disco bangers that preceded their era of early '10s indie" like "1901" and "Lisztomania".
