[2] Uncut felt that the band "have expanded their sound, retaining that youthful energy and combining it with ambition and impressive marshalling of dynamics that creates a strangely serene album", while Mojo remarked that Bdrmm's "murky spider play tugs at the listener's emotions in unanticipated ways".

[2] The Quietus's Zara Hedderman found that it "builds and expands on the successes of its predecessor", from which it "retains a similar wash of reverb-drenched guitars and vocals".

[7] Robin Murray of Clash described the album as "a thrilling return" as well as "an about-turn of sorts, swapping the directness of their debut for an endearing brand of eclectic minimalism".

[4] NME's Thomas smith stated that "where their debut was dark and informed by the early-20s malaise (no wonder it chimed well in COVID's lost years), I Don't Know shows glimmers of hope."

[6] Paul Simpson of AllMusic wrote that I Don't Know contains an "expanded pool of influences, which still include all manner of dreamy, hypnotic rock music, as well as ambient, dance, and classical, incorporating a greater presence of synths and atmospheric textures", also calling the band "consistently inventive, the production is generally fantastic, and the album has several strong moments".