From the Game's Introduction:
Empire of Satanis, EoS, strives for innovation. I tried to go outside the role-playing box with this virgin effort. The layout is minimalist and garage band; it's all about the words on the page. It's akin to Lovecraft on an acid trip hurriedly transcribing the insanity of Hell as he falls deeper into the Pit.
New Stuff: The Game Master, GM, is more of a first among equals rather than an insurmountable force directing the players. The players and their characters will have a hand in creating the setting, mood, and activity of each gaming session too. The GM may set the stage, have a few non-player characters at the ready, and have an idea of a possible outcome for the session... but in EoS it is the characters that motivate the story.
Players run characters called Fiends that are part alien, demon, and human. The ambitious fiends who are consumed by the will to power may advance and shape the conquered worlds to their black heart's desire. The ones who fail will be cut down, preparing the way for new and stronger extra-terrestrial devil things. This is the will of the Crimson God Satanis! Characters can live a somewhat restrained existence within their home universe called Yidathroth. Within its hellish borders civilization flourishes; a balance is struck between Fiends, also known as the brotherhood. Ominous sorcery has replaced the technology predominantly used in the old universe, Sha-la.