[1] Allmusic journalist Anthony Tognazzini described & Then Boom as "fizzy, fun retro-glam-electro-pop from beginning to end", also noting the variety of the sounds on the record.

[11] Caroline Sullivan of The Guardian gave the album a similar score, praising it as "crisp electro-rock with a big hook in every tune, and lyrics that present them as a bunch of civic-minded young fellows.

"[9] Entertainment.ie's Lauren Murphy called most of the rapping "cringeworthy", with her overall verdict of the album describing it as "two different, disjointed and discordant bands - neither with any direction, and both offering only minimal splashes of fun.

"[4] There were extremely negative reviews that questioned if BBC Radio 1's promotion of Iglu & Hartly was a joke, as well as criticized the record's cheap and unprofessional-sounding production and songwriting.

"[2] In a two-out-of-ten review from NME, Rick Martin called it "an abomination of a debut album, informed by all the most disgusting musical faux pas of the past 20 years.