'Killers' is based on more straight-ahead heavy metal, departing from Iron Maiden's 1980 self-titled debut, which had more of a punk edge (a facet often cited as an important stepping stone for 'thrash metal' years later). The best-known track remains the renegade rocker 'Wrathchild,' but other lesser known compositions prove just as strong, such as the gruesome 'Murders in the Rue Morgue;' the singles 'Purgatory' and 'Twilight Zone;' plus the fan favourites 'Innocent Exile,' 'Genghis Khan,' 'Prodigal Son,' and the title track. 'Killers' cemented Maiden's standing as one of heavy metal's most promising up-and-coming bands.