Musically, the sound of 100 Broken Windows has been described as indie punk, and was compared to 1980s alternative acts, such as R.E.M. and Hüsker Dü. Woomble said the Smiths served as a big influence on the album. The album saw Woomble sing in his own accent, in contrast to the previous releases where he leaned towards a more American vocal. Rich Hughes of The Line of Best Fit said the band got the "mix perfect between their REM-influenced literary rock and their punk past". Ink 19 writer Marcel Feldmar said it "conjures up some of the best moments of Swervedriver, and at other moments you just get lost in the power and passion, pulling in a ferocity like the New Model Army up in arms again". Discussing the title, guitarist Rod Jones said Woomble had written it in a book sometime prior, and that it dealt the album's topical theme of dissatisfaction. Woomble said the lyrics reference subject matter such as postmodernism, the Scottish mountains, crofting, and Gertrude Stein. He said the band were improving as songwriters, "but not so much for the album to lose its raw edges". Jeff Jackson of Sonic said the lyrics bounce between "straightforward declarations and enigmatic wordplay, the songs unfurl their meanings in short bursts and volleys".