Complex sentence: Musically, "Sledgehammer" is an electronic dance song with synthpop, new wave and 1980's music style influences with lyrics using a "sledgehammer" as a metaphor to express the physical effects that are caused by excessive love.
Split into simpler sentences: Musically, "Sledgehammer" is an EDM song with synthpop, new wave and 1980's music style influences. Its lyrics use a sledgehammer as a metaphor to express the physical effects that are caused by excessive love.