From the campaign:
Orbis Terrarum is a game set in a rich, living world and ecology. We like to call the genre 'gritty heroism' - this is low fantasy, not Tolkein, with heroes in the vein of Firefly or Game of Thrones, but also a lot in common with the classic pulp adventures of Conan, Fafhrd and the Grey Mouser, Nifft the Lean, and other heroes of sword and sorcery. We don't have elven kingdoms or dwarven clans, but rather vibrant human cultures and history. Science and magic have equal weight - alchemy and scientific method function alongside each other and compliment the magics of geomancy, earthpower and daemonology.
History is full of the efforts of human cultures, but they are not alone. For centuries men have called creatures from other worlds, from strange spaces and dimensions beyond their own called Pandaemonium, or the Daemon Sea. Some people call them a plague, others servants of the divine: Daemons, Spirits, Gods; it was they that brought about the Fall of the first age, from which mankind is only now recovered.
Although things are often bloodily realistic, both rules and setting allow for heroism as well as grim practicalities. We've an unromantic system rewarding tactical sense, but PCs are tough enough to justify feats of heroism and daring do as well.