The album features guest appearances from rapper Tech N9ne, Slaughter to Prevail vocalist Alex Terrible, country singer/rapper Jelly Roll and All Elite Wrestling wrestler Saraya Bevis.

[6] "Popular Monster" was the last song that founding rhythm guitarist Derek Jones played on before his sudden death on April 21, 2020 from a subdural hematoma.

[7] In 2022, Falling in Reverse released the singles "Zombified", written about "how sensitive society has gotten" and "Voices in My Head", which was initially interpreted as a diss against Machine Gun Kelly before Radke said those claims were false.

[10] On May 7, 2024, the band released the album's true lead single titled "Ronald", which featured rapper Tech N9ne and Slaughter to Prevail vocalist Alex Terrible.

Their experimentation is similar to bands such as Bad Omens and Sleep Token in their unapologetic moves to meld pop and rap with metal.

[16] Simon K. over at Sputnikmusic gave the album a 3.3 out of 5, stating that "On paper, Popular Monster reads like an incoherent, schizophrenic mess, bursting at the seams with surface level influences from an eclectic range of genres and styles, all haphazardly stitched together with a derivative breakdown[...] However, there’s a metaphysical element that adheres this Frankenstein’s monster of ideas and makes it all extremely fun and engaging to listen to.

Luke Nutail of The Soundboard compared Radke to Tom MacDonald, saying: "The best that Falling In Reverse can aspire to on Popular Monster is copying another grifter also better known for an insufferable public persona well above any music.

"[19] Rachel Aimee of Still Listening Magazine gave it a rating of zero, the lowest of all, saying: "It is baffling and decently depressing that a band like Falling in Reverse still have a platform, and a big one at that.