[18] Ryan Ciocco of 411Mania wrote, "Negative Spaces sees Poppy delivering a faithful return to her metal leanings from early this decade but also...synth pop and industrial sounds as well.

"[23] Writing for AllMusic, Neil Z. Yeung stated, "Poppy continues to push the boundaries of heavy music and the limits that genre can impose on an artist.

She revealed that it featured raw, poetic lyrics and versatile sound shifts that highlights themes of self-doubt, deferred growth, and a struggle for motivation.

[19] Tom Morgan of Clash wrote, "A stylish, impactful and accessible collection, Negative Spaces is music for our post-genre, post-everything digital age.

"[14] Shania Richards of Distorted Sound wrote, "This album proves Poppy is more than a metal vocalist, nor is she a mere pop-turned-metal singer; she is gradually evolving into something far greater.

"[20] Rishi Shah of DIY called it "A masterpiece, showcasing her ability to meld reliable sound palettes with some audacious new tricks.