[1] Throughout [Wildheart], Miguel comes off as a seeker lost in a world where dreams, religion, sex and art are tangled up with their own dark, addictive mirror images.

According to AllMusic's Andy Kellman, Wildheart's music is defined less by melody than by the presence of "grinding guitars and mechanical beats", played in the style of contemporary R&B and new wave rock.

[6] Jon Pareles from The New York Times says the alluring but amoral environment of California is a recurring setting throughout the record, which explores Miguel's "clashing impulses further" than Kaleidoscope Dream (2012), "toward love and death, raunch and exaltation, doubt and confidence, salvation and damnation, cynicism and hope";[7] "Gonna Die Young" was written about the dangers of leading a risky lifestyle, while "...Goingtohell" explores themes of human mortality and romance.

[13] Reviewing the album for Rolling Stone, Will Hermes found it "even bolder" sonically than Kaleidoscope Dream,[21] while Q deemed Miguel's take on R&B and rock "quixotic".

[23] In Entertainment Weekly, Kyle Anderson called Miguel's lyrics about romance and thrill in Los Angeles both exciting and balanced,[17] while Pitchfork's Anupa Mistry felt he had improved his songwriting with a sex-positive perspective that was distinct from the lustfulness of most other R&B music: "Languorous and detailed, it transcends the genre's established narratives with a focus on pleasure and partnership instead of one-sided pursuit".

[20] Jesse Cataldo of Slant Magazine compared it to D'Angelo's socially conscious album Black Messiah (2014), finding Wildheart to be "just as relevant, acknowledging the complicated realities of modern sexuality while pushing to expand its horizons".

[24] In a less enthusiastic review, NME critic Ben Cardew lamented some of the guitar elements, writing that they occasionally sounded heavy handed in the manner of arena rock.

Club deemed "Face the Sun" a failed attempt at rock and "What's Normal Anyway" too blunt of a "self-love message" amidst the more subtle songs,[15] while Spin's Andrew Unterberger found the album somewhat inferior to Kaleidoscope Dream, even though he said it broadened that record's musical variety.