"Full Collapse" has been mainly described as a post-hardcore release, while also being labelled as post-punk, emo pop, and hardcore punk. Throughout the album, Rickly's singing switches between crooning to screaming. It lacks some of the typical traits of emo in favor of Johnny Marr-like picking in a minor key, against power chords. Members of other bands and members of the production team contributed various instrumentations to the tracks: Farley with additional guitar on "Understanding in a Car Crash"; Joe Darone of the Rosenbergs with additional vocals on "Autobiography of a Nation"; Tom Schlatter of the Assistant with additional vocals on "Autobiography of a Nation" and "Cross Out the Eyes"; Villanueva with additional guitar on "Autobiography of a Nation" and "Wind-Up"; Giles with strings and melotone on "Paris in Flames"; and Frank Giokas of Unsound with additional guitar on "Standing on the Edge of Summer".