Jeremy Heilman’s review published on Letterboxd :
A preppy young boy leaves behind his idyllic small town to pursue a career as a bubblegum pop idol, only to somehow wind up as the frontman of an aggressive death metal band in Toshio Lee’s frequently hilarious Detroit Metal City. Adapted with reckless abandon from a popular Japanese magna, this movie is anchored by a game performance from the rubber-faced Ken'ichi Matsuyama. Playing the dual role of trendy pop wannabe Negishi and kabuki gone mad Krauser, his exaggerated body language and equal comfort in either role turn this into a mistaken identity comedy par excellence.
Not since This Is Spinal Tap has the absurd world of heavy metal music been so successfully mined for laughs. Director Lee exaggerates everything, which not only captures the spirit of the original cartoon, but also allows for narrative lapses (such as how Negishi actually got cast in this ridiculous role) to matter little. Featuring numerous comedic music performances with absurdly aggressive lyrics (e.g. “I’m a terrorist from hell / I raped my mom last night. / I’ll do my dad tomorrow!”) and four or five episodic narrative arcs, the film runs a bit long, but the laughs come frequently enough that it seems churlish to complain. I remember seeing a headline in Variety a week or two ago stating that a film based on the video game Guitar Hero has been planned. Such a movie would be hard-pressed to top the appeal that this film would have for fans of heavy rock.