Brian Formo’s review published on Letterboxd:
The "Where Is My Mind" remix matched with a zoom in on a character thinking "what the fuck just happened?" is fun! (Even though all of the actors outside of Annabelle Wallis are either terrible or terribly directed.) The midpoint reveal reminds me of the looniest Dario Argento moments. (Both this score mention and loony Argento give Phenomena vibes, except what if that reveal happened earlier?) Malignant definitely feels more like a manga than a giallo, throughout. The dialogue, particularly the short quips to state the obvious, does way too much handholding, however.
Ultimately, it's fun, it's quick, it's bloody. But I feel like a "let's all settle down" is in order. After the reveal it kind of just enters rooms loudly; over and over.